Schleibinger Viskomat NT and Viskomat XL
Schleibinger GerteTeubert u. Greim GmbH
Gewerbestrae 484428 Buchbach
GermanyTel. +49 8086 94731-10
Fax. +49 8086 [email protected]
April 5, 2019
Contents 2
Contents
1 Preface 6
2 Viskomat operation 7
2.1 Setting up . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.1 Connecting the system . . . . . . . . . . . . 7
2.2 Preparation for the measurement of the Viskomat NT 12
2.2.1 Installing the measuring probe . . . . . . . . 12
2.2.2 Installing the sample container . . . . . . . . 12
2.2.3 Mounting the valves for the double wall vessel 12
2.2.4 Position measuring head . . . . . . . . . . . 14
2.2.5 Calibrating the torque sensor . . . . . . . . . 15
2.3 Preparation for the measurement of the Viskomat XL 15
2.3.1 The safety guard . . . . . . . . . . . . . . . . 15
2.3.2 Mounting the valves for the double wall ves-sel for the Viskomat XL . . . . . . . . . . . . 17
2.3.3 Installing the measuring probe . . . . . . . . 18
2.3.4 Installing the sample container . . . . . . . . 18
2.3.5 Installing and removing the outer vessel . . . 19
2.3.6 Position measuring head . . . . . . . . . . . 20
2.3.7 Calibrating the torque sensor . . . . . . . . . 20
2.4 Care and maintenance . . . . . . . . . . . . . . . . . 20
2.5 Network Connection . . . . . . . . . . . . . . . . . . 20
2.6 Getting started . . . . . . . . . . . . . . . . . . . . . 22
2.7 Local operation of the Viskomat . . . . . . . . . . . . 23
3 The measuring process 24
4 Profiles 24
4.1 Profile enter . . . . . . . . . . . . . . . . . . . . . . . 24
4.2 Profile select . . . . . . . . . . . . . . . . . . . . . . 28
4.2.1 Sending the profile to the Viskomat . . . . . . 29
5 Measurement 30
5.1 Start . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.1.1 Measurement Start with start button on theViskomat . . . . . . . . . . . . . . . . . . . . 30
5.1.2 Measurement Start from the browser menu . 30
5.2 Measurement Stop . . . . . . . . . . . . . . . . . . . 31
Contents 3
6 Plot 32
6.1 General information . . . . . . . . . . . . . . . . . . 32
6.2 Plot area . . . . . . . . . . . . . . . . . . . . . . . . 33
6.2.1 Title . . . . . . . . . . . . . . . . . . . . . . . 33
6.2.2 Title Size . . . . . . . . . . . . . . . . . . . . 33
6.2.3 Autoscale x, y, xy, none . . . . . . . . . . . . 33
6.2.4 Subtitle . . . . . . . . . . . . . . . . . . . . . 34
6.2.5 Type . . . . . . . . . . . . . . . . . . . . . . 34
6.2.6 Colour/Output Type . . . . . . . . . . . . . . 35
6.2.7 Drawing position on the sheet . . . . . . . . . 35
6.2.8 Drawing resolution in x and y direction . . . . 36
6.2.9 Angle correction yes/no, angle coefficient,angle offset . . . . . . . . . . . . . . . . . . . 36
6.3 X-Axis area . . . . . . . . . . . . . . . . . . . . . . . 36
6.3.1 Unit . . . . . . . . . . . . . . . . . . . . . . . 36
6.3.2 Probe . . . . . . . . . . . . . . . . . . . . . . 36
6.3.3 Section . . . . . . . . . . . . . . . . . . . . . 37
6.3.4 Tick spacing, Main ticks, Small ticks . . . . . 37
6.3.5 Tick label size . . . . . . . . . . . . . . . . . 37
6.3.6 Tick label precision . . . . . . . . . . . . . . . 37
6.4 Y-Axis 1 . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.4.1 From/to . . . . . . . . . . . . . . . . . . . . . 38
6.4.2 Grid . . . . . . . . . . . . . . . . . . . . . . . 38
6.4.3 Tick spacing, Y - Main ticks, Y - Small ticks . 38
6.4.4 Y - Tick label size . . . . . . . . . . . . . . . 38
6.4.5 Y - Grid label precision . . . . . . . . . . . . 38
6.4.6 Y - Title and Y - Title size . . . . . . . . . . . 38
6.4.7 Data set . . . . . . . . . . . . . . . . . . . . . 39
6.4.8 Unit . . . . . . . . . . . . . . . . . . . . . . . 39
6.4.9 Probe . . . . . . . . . . . . . . . . . . . . . . 39
6.4.10 Approximation . . . . . . . . . . . . . . . . . 39
6.4.11 Line Style . . . . . . . . . . . . . . . . . . . . 43
6.4.12 Line Width . . . . . . . . . . . . . . . . . . . 43
6.4.13 Symbols . . . . . . . . . . . . . . . . . . . . . 43
6.4.14 Symbol Skip . . . . . . . . . . . . . . . . . . 43
Contents 4
6.4.15 Line Colour . . . . . . . . . . . . . . . . . . . 43
6.4.16 Cut yes/no . . . . . . . . . . . . . . . . . . . 43
6.4.17 Cut sections . . . . . . . . . . . . . . . . . . 43
6.5 Y-Axis 2 . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.6 Legends . . . . . . . . . . . . . . . . . . . . . . . . . 44
6.6.1 Legend Frame on/off . . . . . . . . . . . . . . 45
6.6.2 Legend Background on/off . . . . . . . . . . 45
6.6.3 Legend Position x/y . . . . . . . . . . . . . . 45
6.6.4 Char Size . . . . . . . . . . . . . . . . . . . . 45
6.6.5 Legend Text . . . . . . . . . . . . . . . . . . . 45
6.7 Text . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.7.1 String on/off . . . . . . . . . . . . . . . . . . . 45
6.7.2 Position x / Position y . . . . . . . . . . . . . 45
6.7.3 Char Size . . . . . . . . . . . . . . . . . . . . 45
6.7.4 Text Colour . . . . . . . . . . . . . . . . . . . 45
6.8 Lines/Arrows . . . . . . . . . . . . . . . . . . . . . . 46
6.8.1 Arrow Style . . . . . . . . . . . . . . . . . . . 46
6.8.2 Arrow Size . . . . . . . . . . . . . . . . . . . 46
6.8.3 Colour . . . . . . . . . . . . . . . . . . . . . . 46
6.9 Text of the header . . . . . . . . . . . . . . . . . . . 46
6.9.1 Text on/off . . . . . . . . . . . . . . . . . . . . 47
6.9.2 Char Size . . . . . . . . . . . . . . . . . . . . 47
6.9.3 Text Colour . . . . . . . . . . . . . . . . . . . 47
6.10 Footnote text . . . . . . . . . . . . . . . . . . . . . . 47
6.10.1 Text on/off . . . . . . . . . . . . . . . . . . . . 47
6.10.2 Char Size . . . . . . . . . . . . . . . . . . . . 47
6.10.3 Text Colour . . . . . . . . . . . . . . . . . . . 47
6.11 Creating the drawing . . . . . . . . . . . . . . . . . . 47
7 Data 49
7.1 XCel . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
7.2 VSC . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
7.3 Database . . . . . . . . . . . . . . . . . . . . . . . . 52
7.4 Datasets . . . . . . . . . . . . . . . . . . . . . . . . . 52
8 Viskomat 52
Contents 5
9 Online display 53
9.1 Configuration in the Controlbar . . . . . . . . . . . . 53
9.2 Infos in the Header . . . . . . . . . . . . . . . . . . . 53
9.3 The sidebar . . . . . . . . . . . . . . . . . . . . . . . 54
9.4 Multigraph . . . . . . . . . . . . . . . . . . . . . . . . 54
10 System 56
10.1 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10.1.1 Height Adjust . . . . . . . . . . . . . . . . . . 56
10.1.2 Sampling rate . . . . . . . . . . . . . . . . . . 57
10.1.3 Averaging Rate . . . . . . . . . . . . . . . . . 57
10.1.4 Filter cut-off frequency . . . . . . . . . . . . . 58
10.1.5 Max. torque . . . . . . . . . . . . . . . . . . . 58
10.1.6 Vessel Start Speed . . . . . . . . . . . . . . . 58
10.1.7 Shear-Stress Factor . . . . . . . . . . . . . . 58
10.1.8 Measurement Range . . . . . . . . . . . . . . 59
10.1.9 Temp. measurement yes/no . . . . . . . . . . 59
10.2 Addresses . . . . . . . . . . . . . . . . . . . . . . . . 59
11 Home 59
12 Help 59
13 Probe Calibration 60
13.1 Viskomat NT . . . . . . . . . . . . . . . . . . . . . . 60
13.2 The Basket Probe . . . . . . . . . . . . . . . . . . . 62
13.3 Viskomat XL . . . . . . . . . . . . . . . . . . . . . . 63
13.4 Non Newtonian Fluids . . . . . . . . . . . . . . . . . 66
13.5 The Vane Probe . . . . . . . . . . . . . . . . . . . . 67
13.6 Comparing the Vane and the Mortar Probe . . . . . 69
14 The Chiller UKH 67.2 71
15 Packing List: 73
1 Preface 6
1 Preface
Congratulations on buying Viskomat rheometer! You have pur-chased a powerful, modern tool for your building materials labora-tory (fig. 1).
To help you make full use of the Viskomat and preserve its func-tionality, this operating manual contains everything you need toknow about setting up, connecting, operating and programmingyour measuring device.
If you read the operating manual carefully, you will soon becomefamiliar with all the features the Viskomat has to offer.
To prevent electric shock, never open the housing. Please leaveany repairs and maintenance to qualified technicians.
Never open the system to try and repair it yourself - always contactthe manufacturer.
Protect the device from liquids. If any liquid gets into the deviceaccidentally, unplug it and contact us. Do not try to continue usingthe device.
Figure 1: Rheometers Viskomat NT and Viskomat XL.
2 Viskomat operation 7
2 Viskomat operation
2.1 Setting up
The Viskomat should be set up on a level, horizontal, vibration-free surface. If necessary, you can turn the feet to adjust them toan uneven surface. We recommend a table of at least 140 x 80cm. To operate the system, a PC with a network connection isstrongly recommended. See section 2.5 for details. If a closed-circuit cooler is used, it should be set up underneath the table, en-suring adequate ventilation. The Viskomat requires a 120V-240 Vand 50-60 Hz, 800 W power connection. The closed-circuit coolerrequires a 2 kW connection. Find the required voltage and fre-quency on the type label.
Never set up the system close to a heat source or where it will beexposed to direct sunlight for long periods.
When setting up the electronics unit, make sure there is adequateventilation, and in particular that the holes on the front and bottomof the system are not covered.
2.1.1 Connecting the system
The Viskomat comprises three units: the measuring device itself,the associated electronics unit and the monitor. All must be con-nected using the appropriate cables. The corresponding socketsare marked on the back of the electronics unit. Connect the indi-vidual units to the electronics unit as follows (see figures 2, 3 and4):
• the lift unit to the Lift socket, until 2010 a black AMP con-nector with a bayonet socket was used. Fix this connectorby turning it 90 degrees. Since 2010 the silver connectoris screwed to the socket (see figure 5) From 2011 a for theViskomat NT a Lemo connector is plugged into the socket.Please don’t turn this connector, only push or pull for remov-ing (see figure 6).
• the drive unit to the Motor socket. This is a push/pull con-nector. Please don’t screw it.
• the measuring head to the Sensor socket, Also a push/pullconnector.
• the monitor to the Monitor socket
• The mouse to the green PS/2 Mini-DIN connector or take theUSB connector
• The keyboard to the magenta PS/2 Mini-DIN connector ortake a free USB connector
• the safety switch of the Viskomat XL to the cable comingfrom the lift unit. If the safety switch of the Viskomat XL isnot connected it will not work!
2 Viskomat operation 8
Figure 2: Connectors on the backside of the Viskomat electronic
Figure 3: Connectors on Viskomat NT
2 Viskomat operation 9
Figure 4: Connectors on the backside of the Viskomat XL. Since2011 the lift connector is beneath the motor connector.
Figure 5: Connector for the Viskomat XL lift unit, used since 2010
2 Viskomat operation 10
Figure 6: Connector for the lift unit, used since 2011
Connect the electronics unit to a 110..230 V/50..60 Hz AC socketwith protective earth conductor. For your own safety, make surethere is nothing standing on or rubbing against the power cable.
The cooling and heating unit should not be placed in a wardrobeor cabinet because it is producing waste heat.
Switch on the system with the power button (see figure 7, 8). Thepower switch is on the top of the electronics unit. First the LEDbelow the mains switch is blinking When you press the power but-ton, the LED is permanently blue. About 2 minutes after bootinganother red LED is on. If the red LED is on and you press thepower button shorty, the LED will be off and the power supplyof the motors is interrupted. If you press the power button shortlyagain, after 1 minute, the LED is going to red again, and the powersupply of the motors is on again.
If you pressure the power button for a longer time, the system isgoing down. Please shut down the system usually with the iconon the desktop.
Be sure that the main power switch on the rear side is on. Theventilation openings on the front of the Viskomat electronics unitmust never be covered!
If the motor power supply is off an alert window pops up on thescreen as shown in figure 9. You may switch it on by pressing theok button, or by pressing the mains button shortly. This works onlyif the safety guard of the Viskomat XL is closed (see chapter 2.3.1)
2 Viskomat operation 11
Figure 7: Power Switch, USB ports, status LED, version 1
Figure 8: Power Switch, USB ports, status LED, version 2
Figure 9: Alert Window popping up if the motor power supply isoff
2 Viskomat operation 12
2.2 Preparation for the measurement of the Viskomat NT
2.2.1 Installing the measuring probe
The measuring probe has a flat side at the top. Insert the probeinto the sensor opening such that the flat side faces the fixingscrew. Fix the probe in place by tightening the screw.
Don’t apply to much torque, otherwise the hollow shaft of theprobe will be bended. If necessary, check that the probe is parallelto the lift unit and in the topmost position by undoing and refasten-ing it.
Load the installed probe slightly in the direction of rotation of thedrive.
Before using a new measuring probe, make sure that it fits into thesample container by winding down the measuring head as far asnecessary with the hand wheel or the up/down buttons (see figure10).
2.2.2 Installing the sample container
If you have a water cooled system with a double wall container,please fix first the outer container with the red marked screw onthe platform mounted on the motor shaft. The mounting fixturefor the sample container consists of two fixed stops and a spring-loaded element or a fastening screw. The two stops accuratelydetermine the position of the sample container. The spring-loadedelement or fastening screw, which is marked with a red dot, pressesthe container into the intended position.
If your model has a spring-loaded element, press the sample con-tainer into the mounting fixture vertically from above, with the flatside facing this element. The sample container is now fixed inplace (see figure 11).
If your model has a fastening screw, press the sample containerinto the mounting fixture vertically from above, with the flat sidefacing the fastening screw, and tighten the screw. This shouldbring the surface perpendicular to the screw. Check whether thecontainer is fixed at the very bottom by undoing and re-tighteningthe screw.
2.2.3 Mounting the valves for the double wall vessel
For cooling and heating the specimen a double wall container isused. Water is circulating through the outer vessel. The water issupplied by two tubes. This tubes are mounted on the left sideof the Viskomat, and may be shifted up and down to remove theouter and inner vessel. Fig. 12 shows the normal position. Openthe black star-formed screw to move the tubes up and down. Becareful that no tube is touching the vessels or the screws inside
2 Viskomat operation 13
Figure 10: Fastening the probe into the Viskomat NT.
Don’t open this screws
Tight this screw to fix the container
Figure 11: Installing the sample container.
2 Viskomat operation 14
the vessel. Mount the tubes as low as possible, to avoid a collisionbetween the measuring had and the tubes. Close the valves atthe end of the tubes before you lift the tubes up, ore before youremove, to be sure that no water is lost, and no air comes intothe circulation. Figure. 13 shows the position of the tubes formaintenance and service.
Figure 12: Tubes in the right position
Figure 13: Tubes in the maintenance position, you may now re-move the double wall container.
2.2.4 Position measuring head
When you start the measuring program, the measuring head au-tomatically moves to the correct position.
To move the measuring head up and down yourself, use the UPand DOWN buttons. Keep the button depressed until the deviceresponds. The measuring head will move down until you releasethe button.
If the device is switched off or if you want to position the measuringhead slowly or precisely, you can also use the handwheel on thetop of the lift unit.
2 Viskomat operation 15
2.2.5 Calibrating the torque sensor
Calibrating the gain The device is factory-calibrated at severalcalibration points for both measurement ranges and for clockwiseand anti-clockwise rotation. This calibration is not lost during nor-mal operation, but if the torque sensor is overloaded or damaged,calibration should be repeated. In this case, please contact cus-tomer service.
Calibrating the zero offset When the device is switched on ora new profile is loaded, the zero offset of the torque sensor is cal-ibrated automatically also before staring the measurement. Afterinstalling the probe, slightly load the torque sensor once in thedirection of rotation of the drive before measuring.
2.3 Preparation for the measurement of the Viskomat XL
2.3.1 The safety guard
Due to the big forces of the instrument, the Viskomat XL has aso called safety guard (see figure 14, left). The operation willbe stopped if the safety guard is open, or if the safety guard ispressed downwards. So please close the safety guard before starta measurement.
Be sure that the connector of the safety guard is connected. Oth-erwise the safety switches will not work. When the safety guard isopened, for example for placing the vessel (see figure 14, right),you will hear the sound of a buzzer. The red LED on the front ofthe electronic is switching off. To activate the system again youhave to close the safety guard, and press the main button shortly,or confirm the message in the appearing pop up window on thescreen. The red LED must switch from off to on again.
If the safety guard is opened 2 popup windows will appear on thescreen and you will here a short sound of the buzzer. One alertwindow signals the opened safety guard. You may simply confirmthis window, then it will disappear.
The other alert window indicates that’s the motor power supplyis off. Please close the safety guard and press the ok button toswitch the motor power supply on. Se figure 15 and 16. Thewindows are in German and English.
If you are touching the safety guard during the measurement, orif the lift is going up or down, all movements of the motor aresuddenly stopped. Please press the option Viskomat Stopp in themain menu of the software. Then the power supply is switched onagain, and the lift will go up.
If the viskomat XL is used without the safety guard for service ormaintenance use, only special trained persons may work with thesystem.Attention!
2 Viskomat operation 16
Figure 14: The safety guard of the viskomat XL in the working /normal position (left) and in the opened position (right).
Figure 15: An alert window shows that the safety guard is open.
2 Viskomat operation 17
Figure 16: An alert window shows that the motor power supplyis off. Please close the safety guard and press ok to restart themotor power supply.
2.3.2 Mounting the valves for the double wall vessel for the Viskomat XL
For cooling and heating the specimen a double wall container isused. Water is circulating through the outer vessel. The water issupplied by two tubes. This tubes are mounted on the left and rightside side of the Viskomat XL, and may be shifted up and down toremove the outer vessel. Fig. 17 shows the normal position. Openthe two Allen screws a bit to move the tubes up and down. Becareful that no tube is touching the vessels or the screws insidethe vessel. Mount the tubes as low as possible, to avoid a collisionbetween the measuring had and the tubes. Close the valves atthe end of the tubes before you lift the tubes up, ore before youremove, to be sure that no water is lost, and no air comes into thecirculation.
Figure 17: The tubes of the viskomat XL in normal operating po-sition
2 Viskomat operation 18
2.3.3 Installing the measuring probe
The measuring probe has two small cylindrical rods, mounted onthe upper side of the shaft of the probe.
Insert the probe into the sensor opening such that the you arepulling the black star formed knob (see figure 18) to the right sideof the instrument.
The two rods must fit into the slit in the front and the rear side ofthe sensor.
After insertion the probe, release the black knob and the probe isfixed. The connector for the temperature sensor must show to theright side of the instrument.
Load the installed probe slightly in the direction of rotation of thedrive.
Figure 18: Mounting the probe into the Viskomat XL
2.3.4 Installing the sample container
The sample container has red marked slit near the bottom of thevessel.
• Turn the outer vessel slowly by hand until the the red pointis pointing to the front.
• Take the inner vessel, turn it, until the red point is also point-ing to the front.
2 Viskomat operation 19
• Set the inner vessel into the outer vessel and press it intothe spring loaded elements inside the outer vessel.
• Turn the inner vessel about 10 degrees.
• The sample container is now fixed in place (see figure 19).
Figure 19: Installing the sample container for the Viskomat XL.
2.3.5 Installing and removing the outer vessel
For service you may remove the outer vessel (see figure 20).
Open the two Allen screws (size 4) and pull the vessel upwards.
Figure 20: Mounting the outer vessel of the Viskomat XL.
2 Viskomat operation 20
2.3.6 Position measuring head
When you start the measuring program, the measuring head au-tomatically moves to the correct position.
If the device is switched off or if you want to position the measuringhead, you can move it up or down by hand.
2.3.7 Calibrating the torque sensor
Calibrating the gain The device is factory-calibrated at 100,300, 500, 700, 1000, 5000 and 10000 Nmm for clockwise andanti-clockwise rotation. This calibration is not lost during normaloperation, but if the torque sensor is overloaded or damaged, cal-ibration should be repeated. If this is necessary, please contactcustomer service.
Calibrating the zero offset When the device is switched on, thezero offset of the torque sensor is calibrated automatically. Alsobefore staring the measurement. After installing the probe, slightlyload the torque sensor once in the direction of rotation of the drivebefore measuring.
2.4 Care and maintenance
All moving parts of the device are lubricated for the long-term andare maintenance-free. Do not use caustic solvents, jet-water orabrasive cleaning agents to clean the device. Instead, use a clothdipped in washing-up liquid water and follow up with a dry cloth.For the stainless steel parts you can also use ordinary stainlesssteel cleaning agents.
2.5 Network Connection
The Viskomat features the latest Internet technology. This meansthat it is controlled via an Internet-compatible network. This re-quires an Ethernet network with a transmission rate of 10, 100 or1000 Mbit/s and the TCP/IP protocol. The electrical connection ismade via a category-5 Ethernet cable with RJ45 plug connectors.Before the Viskomat is switched on, the cable must be connectedto the network or, in the simplest case, to another PC using across-wire cable (fig. 21). The control PC must meet the followingrequirements:
• Ethernet connection with 1000, 100 or 10 BaseT and TCP/IPprotocol
• Internet browser installed
Viskomat control is independent of the operating system. Systemsthat may run on the control PC include:
2 Viskomat operation 21
• Windows 95, 98, 2000, ME, NT, XP, Vista, Windows 7... Win-dows 10
• Linux, UNIX, MacOS, FreeBSD, Solaris, ...
A fixed Internet address may be assigned for the Viskomat. Thefactory-assigned address is 192.168.1.xxx, where xxx is between11 and 255. Default 192.168.1.55 is set. DHCP server may beused as well.
The address is shown on the system or can be obtained fromSchleibinger. The Viskomat is addressed from the control PC us-ing this address, for example with http://192.168.1.55
The network connection is best tested with the ping program. Un-der Windows, for example, you can call this via the MS-DOS shellwith ping 192.168.1.55. If there is no network connection to theViskomat, the program issues an error message.
Cache size in the browser should be set to 0 Kbytes. The browsershould be set to reload Internet pages each time they are re-trieved. Using the option Reload page (or similar), you can alsoactivate this manually for each individual page.
Viskomat NT
Intranet
Internet
EthernetICP/IP
Win NT 2000
Mac OS, UNIX
Explorer, Netscape
Netscape, StarOffice...
Komunikation Viskomat NT u. PC
Telco/LAN Router
Figure 21: Network connection of the Viskomat.
2 Viskomat operation 22
2.6 Getting started
Once the network connection is set, switch on the Viskomat bypressing the switch on the frontside shortly. During startup, anumber of messages will appear on the attached monitor. Afterapprox. two minutes, a brown window is displayed containing therequest for your username. Schleibinger is set as default, andshould be preferred.
Enter the password: viskomat. Please write the password withsmall caps. Now start a browser such as Firefox, Netscape, Mozilla,Internet Explorer, Opera etc. on your control PC.
Enter the IP address of the viskomat in address line of the browser:http://xxx.xxx.xxx.xxx. Default is e.q. 192.168.1.55. You candefine this number as the start page or as a bookmark in yourbrowser (see your browser manual).
The following start page is displayed in your browser (figure 22).If the page is not fully visible, you can bring the rest of it into viewusing the scroll bars along the right edge of the window. At thebottom of the start page you will see a German flag (black, red,gold) and a British flag (red, white, blue). Select the language forthe operation of the Viskomat by clicking the suitable flag. Afterselection of the British flag, the Viskomat main menu is displayed(see figure 23).
Figure 22: Start page in your browser (here Mozilla Firefox)
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Figure 23: Main menu for operating the Viskomat NT from withinthe Internet browser
On the left part menu bar is located. You can click any item under-lined in blue. The corresponding page will then be displayed in theright part of the window. By clicking on the slightly larger superor-dinate menu items, you will get a brief online help. By clicking onthe subordinate items, you will call up the corresponding functionsdirectly.
2.7 Local operation of the Viskomat
The Viskomat may operated from a control PC, but you can alsooperate it locally without a control PC. To do this, proceed as fol-lows:
• Connect mouse to the Viskomat control unit.
• Connect a keyboard to the Viskomat control unit.
• Switch on the Viskomat NT.
• Log in as user Schleibinger at the login prompt.
• Enter viskomat as the password. Note that it is written all inlower case.
• Start the browser by clicking the web browser symbol.
• Enter localhost or the IP number, for example 192.168.1.55
as the address.
• Operate the Viskomat as described earlier.
3 The measuring process 24
• Before switching off the Viskomat, exit all the programs byclicking the ’close’ icons (x).
• Click the red door or power switch symbol in the task bar.
• Click Log off.
3 The measuring process
T his chapter describes the individual steps involved in taking aViskomat measurement. The process comprises 6 or 7 steps tobe performed on the Viskomat:
• Defining the job,so-called profile.
• Sending this profile to the Viskomat.
• Assigning a name to the measurement and starting the mea-surement.
• Measurement end or stopping the measurement.
• Graphical evaluation and display of the measured data.
• Exporting and saving the measured data.
• Basic system settings.
4 Profiles
The job or program to be performed by the Viskomat is defined ina so-called profile.
4.1 Profile enter
To enter a new profile, proceed as follows:
Click the item Profile Enter in the left menu bar. The corre-sponding input mask is displayed in the right part of the window.This mask is divided into six sections.
In the first line select whether you want to enter your profile ineither steps or ramps.
Explanation:
Usually the Viskomat records moments of resistance on the stir-ring body as a function of different speeds. In the profile you candefine how long the different speeds are to be applied. By spec-ifying these entries in so-called steps, you define how long eachspeed is to be applied before changing to the next speed.
By specifying these entries in ramps, you define within which pe-riod of time the Viskomat has to accelerate from speed a to speedb.
For a ramp specification the entry 5 minutes and 120 rpm meansthe Viskomat will accelerate the rotational speed from 0-120 rpmwithin 5 minutes.
4 Profiles 25
For a step specification with the same values, the Viskomat willrotate at 120 rpm for 5 minutes.
Enter the profile name in the next field. You can retrieve the pro-file under this name at any time and modify it or send it to theViskomat again as a new job.
The name can be up to 128 characters long and can contain di-acritical characters, but not spaces and not dots! Use underlinesinstead of spaces. Note that the Viskomat differentiates betweenupper and lower case in all file names. So, for example, the filenames MILLER (all upper case) and miller (all lower case) are notidentical! Spaces and dots will be automaticly replaced by under-lines.
The next section with a large white field a comment of up to 64,000characters for each profile can be entered. In this field specialcharacters and spaces are allowed.
The specificaton of the measuring proben will be done in the nextsection. The type of stirring body selected determines how farthe measuring head moves down into the sample container. Theitems Mortar or Cement paste are identical, as both stirring bodieshave the same length.
The next section contains the buttons Save, Reset and Save and
Send to the Viskomat:
Save - saves the profile you have entered under the specified filename.
Reset - quits the menu item without saving any changes.
Save and Send profile to the Viskomat - saves the profile andsends it to the Viskomat at once. The Viskomat is ready to bestarted with this profile.
In the next section you define the profile. The profile is entered ina table. There are 30 table rows available, each with four columns.In the first two columns you enter how long each step is to take.This is entered as the absolute duration of the measurement.
In the third column enter the value, e.g. the speed; in the fourthcolumn define the measurand via a selection bar. You can choosefrom the following:
• speed (rpm)
• degrees (to specify a fixed angle
• Newton millimetres (Nmm, this is used to specify the torque;the corresponding speed is regulated - the so-called torquecontrol (optional)).
• Hz f-ramp = frequency sweep: oscillation with a certain am-plitude at a fix frequency (using step profile) or increasingfrequency (using a ramp profile). You have to define the
4 Profiles 26
constant amplitude in degrees in the 5th column of the pro-file table.
• Hz a-ramp = amplitude sweep: oscillation with a certain fre-quency at a fix amplitude (using step profile) or increasingamplitude (ramp profile option). You have to define the con-stant frequency in the 5th column of the profile table.
One possible measurement profile is a step profile and is shownin figure 25 and in figure 24 in graphical form.
Figure 24: Enter Profile mask
Zeit / min
Geschw. / Upm
120
80
40
10 14
Figure 25: Step profile as entered in figure 24
4 Profiles 27
An other possible measurement profile is a ramp profile and isshown in figure 26 and in figure 27 in a graphical form1. Pleasenote that here fixed points of an arbitrary speed curve are speci-fied rather than individual speeds.
Figure 26: Enter profile as ramps
Zeit / min
Geschw. / Upm
120
80
40
10 145
Figure 27: Measurement curve according to ramp profile as en-tered in figure 26.
Basically, it is also possible to mix the individual targets, e.g. firstrunning a speed of 1 rpm, then changing to torque control, i.e.specifying a torque. The lowest speed that can be specified is0.001 rpm, and the maximum is 300 rpm for the Viskomat NT and
1 Geschw./Upm = Speed/rpmZeit/min = Time/min
4 Profiles 28
80 rpm for the Viskomat XL. Please note, in the case of torquecontrol the maximum speed is about 4 rpm.
Make sure that the required torque will be reached by selecting anappropriate material and measuring geometry. Also bear in mindthat torque control is not infinitely fast, and that, for example, aftera shear-induced breakdown, no new torque can be built up.
When you click the Save or Save and Send button, the messageProfile will be saved, the profile name and the full file name willappear in the right part of the window.
To return to the main menu, click Home at the bottom of the window.
4.2 Profile select
For selection of a profile already saved for the Viskomat, clickProfile Select in the menu bar. The basic file selection maskis displayed, which is used in several places in the Viskomat pro-gram. Click OK to display all the saved files in a table.
If there are a large number of saved measurements, this displaymay become confusing. To avoid this you can click Select in thesecond line to limit the number of files for display. Here you canenter two criteria:
The file name:
If you enter, for example, the file name combination m* the systemwill only display files which start with the letter m. If only * isentered in this line, all files are displayed.
In the next line you can specify the time the file was created, e.g.younger than - one week, by clicking the corresponding selec-tion bar. Other possible values include older than - one year
and younger than - 24h plus any combination of these values.
In the next line you can specify whether the comment saved withthe profile is containing a specific context. If you find all thesepossibilities too confusing, just click OK to display all the availablefiles (see figure 28).
Once you click OK, the system displays a list with the profile filesin a three-column table. The second column contains the name ofthe profile file, the third contains the associated comment.
The first column contains a selection symbol in the form of a blueX. Click the cross next to the profile you want to select. The Enter
Profile mask is displayed containing the profile data.
Select Save and Send or modify the profile, save it again and sendit to the Viskomat, or discard your changes.
4 Profiles 29
Figure 28: File selection mask as used at several points/places inthe program
4.2.1 Sending the profile to the Viskomat
When you click Save and Send, the profile data is sent to theViskomat control electronics. This takes approx. 20 seconds, dur-ing which time the status is displayed on the screen. Please, waituntill the following massage appears showing a successful profiledownload see figure 29.
If the profile has been successfully transferred to the Viskomat,you will see the profile name in the online display of the Viskomat.
Figure 29: Successful profile download.
5 Measurement 30
5 Measurement
This menu section allows you to start or stop the Viskomat.
5.1 Start
Different ways for starting a measurement with the Viskomat areavailable.
5.1.1 Measurement Start with start button on the Viskomat
The Viskomat NT has a green start button on the measurementhead. By pressing this button the system automatically assigns afile name consisting of a current date and time followed by the filename extension .dat.
The Viskomat XL should be started from the browser menu only.Attention!
5.1.2 Measurement Start from the browser menu
The second way of starting a measurement is via the main menuitem Measurement Start. When you select this item, a menu withtwo input boxes is displayed (figure 30). In the first box you canspecify a file name.
This file name can be up to 128 characters long and do not containdots ore spaces. Diacritical characters are allowed, and upperand lower case are differentiated. You must not use dots. If youdo not specify a file name, a unique number will automatically beassigned for the file name. This will be made up of the actual dateand time, followed by the file name extension .dat.
If the specified file name already exists, the file will be over-written without a warning!Attention!
It is necessary to input a specimen number. Any number or letteris allowed here.
Further information in the fields below can be added e.q.for w/cratio etc. This is optional and the fields can be left blank.
In the input box on the bottom of the screen you can enter a com-ment of up to 64,000 characters. You can also edit this commentlater. In the top and bottom part of the mask is the Start button,which you click to start the Viskomat.
Note: It takes about 15 seconds from the time you click Start untilthe measurement actually begins. The Viskomat needs this timeto calibrate the measuring head, move down into the sample andstart the motor.
5 Measurement 31
5.2 Measurement Stop
The measurement can be stoped at any time by pressing the redbutton on the measuring head of the Viskomat or by selecting themenu item Measurement Stop.
By selecting the menu item Measurement Stop a confirmation isneeded to make sure the measurement have to stop.
The Viskomat XL may be stopped by the internet browser or fromthe safety switch of the safety guard (see also chapter 2.3.1). Ifyou are opening the safety switch the motor and the lift are au-tocratically stopped. The LED on the front side of the computeris changing from yellow to green. Close the door and press themain button again to continue operation. If you are opening thesafety switch during a measurement the task will be interruptedand not continued, if you close the switch again. A stopped mea-surement is not discarded but can be evaluated up to the time itwas stopped.
Figure 30: Measurement Start by entering the file name andcomment
6 Plot 32
6 Plot
6.1 General information
Plot allows you to display the measured data graphically in differ-ent variants. When you click this menu item, the usual file selec-tion menu is displayed. Click OK to list the measurement files. Thesecond column contains the file name, the third column containsthe associated comment. In the first column you can click the fileswhose data you want to display graphically.
The mask contains the button Display parameter file. This fileis used to save the settings which define how the measured datais to be displayed, e.g. the selected section, curve colour etc.This information is saved separately from the measured data itself.Select a display parameter file for your measured data and clickthe Drawbutton.
A vertically-split window will appear. The top part contains a smallgraphic (in figure 31 a graph) symbolising the graphical display. Inthe top left of the window you will see an ’up’ arrow. The bottompart of the window contains approx. 70 input fields, in which youcan define how you want your graphical display to look. To movefaster through the lengthy input mask, you can use the symbolicgraphic at the top. This is in fact a clickable map (see figure 31).
Figure 31: Clickable or context-sensitive map
Explanation: The symbolic graphic contains the most importantparts of a graphical display of measured values, e.g. y-axis, x-axis,legend, header When you move the mouse pointer over theseparts of the graphic, the arrow changes to a hand. For example, ifyou move the mouse pointer over the x-axis, the arrow changes to
6 Plot 33
a hand. If you then click the x-axis, the bottom part of the windowautomatically scrolls to the area where you can enter the data forthe x-axis.
By clicking the Legend area, you can scroll to the part of the inputmask where you can enter text for the legend. You can return tothe beginning of the input mask by clicking the blue-and-white ’up’arrow. Try this by clicking different parts of the symbolic graphic.The input mask for the graphic is divided into different sections:
• In the first part you can make all the basic settings for thegraphic, e.g. headers, size etc.
• The second part defines the settings for the x-axis.
• This is followed by the input masks for all the y-axes.
• Then comes the area for entering a legend and two othertext areas.
• At the end of the mask you will find the input areas for mark-ing arrows as well as for text to be added above and belowthe graphic itself.
Do not worry about the number of possible entries. For a quickgraphical representation you usually only need to select the mea-surement file and the measurands you want to display on the x-and y-axes, e.g. the temperature or the revolutions per minute.Then click the option Autoscale in the top part of the input maskand click the Draw button at the beginning of the mask to createthe graphic.
Many of the input fields are marked blue. This means you can callup online help on these fields. The individual fields are describedbelow.
6.2 Plot area
The input mask is shown in figure 32.
6.2.1 Title
Here you enter the main title to be displayed above the chart.
6.2.2 Title Size
Here you enter the size of the main title. You can choose fromsizes 1 .. 4.
6.2.3 Autoscale x, y, xy, none
If you select autoscaling xy, the program tries to select an optimumdetail for your measured data, depending on the actual measureddata. If you set only x or y only one of both axes is set automati-cally. If this option is set to none, you must enter the scaling of the
6 Plot 34
Figure 32: Input mask Plot, Plot area
x- and y-axes manually. The distance between the lettering andbetween the grid lines must also be entered. This is done in theX-Axis and Y-Axis areas.
6.2.4 Subtitle
Here you enter a subtitle to appear below the main title in a smallerfont.
6.2.5 Type
Three types of graphic are currently supported:
Type Explanation
XY Plot Normal graph representing the measured values in alinear coordinate system.
Log X - Linear Y The x-axes is set logarithmic, the y axes keepslinear
Log Y - Linear X The y-axes is set logarithmic, the x axes keepslinear
Log Y - Log Y Both axes are set logarithmic to a logarithmicscale.
6 Plot 35
6.2.6 Colour/Output Type
The following options are available:
Colour/JPEG An on-screen graphic is created in the JPEG for-mat. This graphic is displayed directly in the Internet browser, incolour or in grey levels. This is the default option and is supportedby any Internet browser. The disadvantage is that, depending onyour printer and operating system, the resolution may be too lowfor a high-resolution printout. Try the PNG format (see below) asan alternative.
Option PDF/Acrobat Here the graphic is displayed in the PDFformat (Portable Document Format) from Adobe. The disadvan-tage here is that most Internet browsers do not display it directlybut call up the external program Adobe Acrobat Reader for dis-playing PDF images. This program is available from Adobe freeof charge and is already installed on most PCs. The advantageis that the graphic is a so-called vector graphic, i.e. the quality ofdisplay depends only on the quality of your screen or printer.
This format also makes it easy to pass on measurement curvesand can also be further processed by many graphics programs.
Option PS Postscript Here the graphic is created in Postscriptmode. This is a widespread graphics format, especially in theUNIX environment. It can be used to output the graphic to anyprinter that supports Postscript.
Option EPS Here the graphic is created in the Enhanced Postscriptmode. This is also a widespread graphics format, especially in theUNIX environment. It can be used to embedd grahics in otherdocuments
SVG These is another vector-graphics file formats which can bedisplayed in common Internet browsers or are supported by othergraphics programs. Depending on the browser you are using, re-sults may be quite different.
PNG A free (and better) alternative format to JPEG (which hassome copyright restrictions)
6.2.7 Drawing position on the sheet
Your graphic is shown on a virtual sheet. Here you can definewhere the actual measurement curve is to be positioned on yoursheet. All specifications are between 0 and 1.
6 Plot 36
6.2.8 Drawing resolution in x and y direction
Here you can define the size of your sheet and thus the resolutionin screen pixels. The higher the number, the higher the resolutionof the graphic. However, depending on the screen resolution set,you may find that the virtual sheet is larger than the screen and soonly part of the graphic is displayed.
6.2.9 Angle correction yes/no, angle coefficient, angle offset
These three options are only required for torque control. Theyallow you to correct the deflection of the measuring head relativeto the torque (this is approx. one degree per 200 Nmm and mustbe taken into account when calculating the resulting measurementcurve). In normal operation mode please set the angle coefficientto 1 and angle-offset to zero.
6.3 X-Axis area
The input fields for the x-axis are shown in figure 33
Figure 33: Input fields for the x-axis
6.3.1 Unit
Here you select which of your measurands you want to representon the x-axis. This could be temperature, torque, revolutions perminute, angle, time in minutes or time in seconds.
6.3.2 Probe
If you are working with the standard probes like the mortar orthe cement paste probe you are making a relative measurement.So the flowcurve is the measured torque over the speed in rpm.You can measure the shear stress and shear rate directly with the
6 Plot 37
cylinder-cylinder probe, the basket probe or the cone-plate probe.Then you can choose as shear rate directly τ and shear stressγ̇ . Therefore you have to select here the probe type for correctcalculating the shear stress and the shear rate. If you are usingother units then τ or γ̇ the probe selction has no influence in thedisplayed data.
6.3.3 Section
The next two input fields from/to are for selecting which section ofthe x-axis you want.
If Autoscale is set to on in the Plot area, this entry is invalid.
6.3.4 Tick spacing, Main ticks, Small ticks
Here you enter the scale or lettering of the x-axis. Under Mainticks you can define the distance between the ticks and the cor-responding lettering on the x-axis in physical units. Under Smallticks you specify ticks without lettering on the x-axis. If the Gridoption is activated, lines are drawn in with the distance specifiedunder Small ticks.
6.3.5 Tick label size
Here you define the size of the x-axis lettering. Possible range:0.5-2.0
6.3.6 Tick label precision
Here you can define how precise (decimal fractions) the x-axislettering is to be.
The fields Axis label and Axis label size are currently not used.
6.4 Y-Axis 1
When you start the display of the graphic, you can select howmany measurement files you want to represent. This also deter-mines the number of y-axis input fields available to you. Here theterm y-axis is equivalent to the measurement curve. Only oney-axis is actually displayed, namely y-axis 1.
Example: If you want to display the torque of measurement A andthe torque of measurement B, you select measurement file 1 andmeasurement file 2 respectively in the Data Set field in the Y-Axisarea. If you want to display both the torque and the temperature ofone measurement, select the torque for y-axis 1 and the temper-ature for y-axis 2. In this case, the torque axis is used, e.g. in therange 0-200 Nmm. The temperature is then displayed accordingly.
The input fields for the y-axis area (figure 34):
6 Plot 38
Figure 34: Y-Axis area
6.4.1 From/to
If the autoscaling function is not activated, you can select the axissection here.
6.4.2 Grid
Here you can select whether or not you want a grid to be displayedin the background of the measurement.
6.4.3 Tick spacing, Y - Main ticks, Y - Small ticks
As with the x-axis, here you enter the distance between the ticksand lettering on the y-axis and between the grid lines. As with thex-axis, here you enter the distance between the ticks and letteringon the y-axis and between the grid lines.
6.4.4 Y - Tick label size
Here you define the size of the y-axis lettering.
Possible range: 0.5-2.0
6.4.5 Y - Grid label precision
Here you can define the number of decimal places to be used fory-axis lettering. Here you can define the number of decimal placesto be used for y-axis lettering.
6.4.6 Y - Title and Y - Title size
These fields are currently not used.
6 Plot 39
6.4.7 Data set
Here you select the measurement file to be assigned to the y-axis.
6.4.8 Unit
Here you select which measurand of the measurement is to berepresented.
6.4.9 Probe
If you are working with the standard probes like the mortar orthe cement paste probe you are making a relative measurement.So the flowcurve is the measured torque over the speed in rpm.You can measure the shear stress and shear rate directly with thecylinder-cylinder probe, the basket probe or the cone-plate probe.Then you can choose as shear rate directly τ and shear stressγ̇ . Therefore you have to select here the probe type for correctcalculating the shear stress and the shear rate. If you are usingother units then τ or γ̇ the probe selection has no influence in thedisplayed data.
6.4.10 Approximation
The original measurement files are normally represented in a graphic.This is the case if Original is selected for the Approximation op-tion. If you want to represent a flow curve instead of the originalmeasured data, you can use the corresponding options here. Astraight correction or interpolation line is selected via the optionT=h*n+g. Other non-linear correction curves are also available.For Bulkly-Herschel interpolation use
T=g+a*(N**b)
This means T = g + a(N b). Please note the restricted mathemat-ical definition ranges of some of the functions.
Evaluation of Oscillation Measurements Oscillation modes area quite complex method for studying materials rheological pa-rameters. In opposite to the evaluation of measuring standardflowcurves, here the vessel is sinusoidal oscillating at different fre-quencies and amplitudes. The resulting force on the probe, is alsoa harmonic function, if the material has a linear and time indepen-dent behaviour. There are two standard tests used here.
• With an amplitude sweep, the vessel is oscillating at a con-stant frequency for example 0.5Hz. The amplitude is in-creasing or decreasing.
• With the frequency sweep, the deformation amplitude is keptconstant for example 1 degree but the frequency may in-crease or decrease during the test for example from 0Hz to3 Hz.
6 Plot 40
The test procedure is defined within the profile see chapter 4.1.
We will now focus on the frequency sweep. In the picture 35 youmay see the angle of the vessel over time (black function) andthe measure torque (red curve). You see that the delay betweenstress and strain is varying over time, also the amplitude of thestrain is changing over frequency.
Figure 35: Vessel angle over time, and resulting force on thepaste probe. Material wallpaper paste. Instrument: Viskomat XL
In figure 36 you see the angle δ and the stress τ plotted on theordinate and abscissa. This kind of curve is known as Lissajousfigure.
Its known from the theory of complex numbers that the relationbetween two sinusoidal functions my be expressed as complexnumber G′ + iG′′. You may also write this complex number asG∗cos(δ)+ iG∗sin(δ) where G∗ is the length of the complex vectorand δ the angle between the complex number and the real axis inthe complex plane (see figure 37).
In the oscillation rheology the real part G′ is called storage modu-lus, because this number describes the elastic component of thematerial, and G′′ is called loss modulus, it is describing the plas-tic properties of the material. Normally the behaviour of G′ andG′′ is displayed over the angular speed ω where ω = 2πf andf is the oscillation frequency in Hz. Select ω/1/s in the X-axissetup of the menu. The plot is normally done in a double log way.Select this in the Layout part of the menu chapter 6.2.5. SelectType : Log X - Log Y. An example is shown in figure 38.
6 Plot 41
Figure 36: Torque over angle. A typical Lissajous figure. Materialwallpaper paste. Instrument: Viskomat XL
G’
G’’
δG*
Re
Im
Figure 37: Calculation G′ and G′′ from the ellipse
The program is offering 4 calculations for δ, tan(δ), G′ and G′′
The calculation of this parameters is not a trivial task, becausemost of the real materials have no linear response and are stronglytime dependent. The signals may be often noisy if we have a in-homogeneous material. In the literature this problem is often sub-sumed under the topic large amplitude oscillatory shear (LAOS).The often suggested FFT technique doesn’t work for short sweepsand for non linear responding material.
The algorithm for the Viskomat is as follows:
1. Draw the Lissajous ellipse for a 2π angle of stress
6 Plot 42
2. Calculate the major and minor axis plus rotation angle. Thisis be done by using the inverse of the Covariance Matrix forall points of the ellipse. G∗ is the has the length and thedirection of the positive major axis. G′, G′′ δ and tan(δ) maybe easily calculated from G∗.
3. Go 2π further and go to step 1.
The disadvantage of this algorithm is, that it lasts about 1 minutefor about 100000 sampling points, calculated on the 800MHz pro-cessor of the Viskomat An intelligent algorithm tries to find out, ifa new calculation is necessary, or if already calculated data canbe used again.
The source code for this algorithm is in the file ellipse_covarianz.m
in the subdirectory /usr/local/httpd/cgi-bin. It is a Matlab (R)like program, and handled by the GNU/Octave software installedon the Viskomat.
For filtering the results there is a new option in the plot menu ineach Y section. Its called curve smoothing, and at the momentonly applied for the oscillation measurement evaluation. Thereare 4 options no, weak medium and strong.
Figure 38: G′ and G′′ over the frequency. Material wallpaperpaste. Instrument: Viskomat XL
6 Plot 43
6.4.11 Line Style
The usual line style is continuous lines connecting all measure-ment points. You can also use dotted and dashed lines for therepresentation in order to differentiate the individual curves moreeasily, especially in a black-and-white display.
If None is selected for the line style, the measurement curve is notrepresented using lines but the measured values are displayed assingle points. In this case, you can select a symbol to be used forthe values.
6.4.12 Line Width
Here you can define the thickness of the drawn line.
6.4.13 Symbols
If you select the option No here, the measurement curve is dis-played as continuous lines. If you select a symbol, a graphicalsymbol is added between each measured point.
You can chose from a wide range of symbols: circles, crosses,squares etc
6.4.14 Symbol Skip
If you have selected a symbol, you can define here whether eachmeasured value is to be represented by this symbol or only everyxth value. Here you enter the number x.
6.4.15 Line Colour
Here you define the colour in which the curve is to be displayed.A total of 16 colours are available. Please bear in mind that somecolours do not come out very well on colour printers (e.g. yellow).
6.4.16 Cut yes/no
This function is especially important if you want to define a flowcurve. Here it is often useful to only show specific parts of ameasurement curve or use only specific parts for the calculation.Which parts are cut out is defined at the bottom of the input mask.
6.4.17 Cut sections
As mentioned above, specific parts of the measurement can bedefined for inclusion in the graph - especially for flow curve rep-resentations. The entries in these fields always refer to the mea-suring time in minutes. This also applies if you represent, say, thetorque as a function of the speed. You can enter a maximum of fiveranges by defining a from minute and to minute for each of them.
6 Plot 44
Each curve can be cut out separately. This allows you, for exam-ple, to display several flow curves for individual cut-out ranges of ameasurement. If you want to enter sections in seconds, you mustenter the time as a decimal fraction.
6.5 Y-Axis 2
If you have selected more than one measurement curve, an in-put field for the y-axis will be set up for each measurement curve.These input fields are identical as of y-axis 2. As with y-1, all en-tries are possible here, except for the scaling, which is determinedby y-axis 1.Important note:
If you want to represent, say, the torque changes and the flowcurve of a measurement at the same time, this means drawingtwo curves. Therefore, in the file selection menu you will need toselect your desired measurement file plus any other measurementfile, so that the program opens the option for two measurementcurves (original and flow curve!) and you can enter and displayyour input.
6.6 Legends
A legend function is available for labeling the drawing. This canbe activated/deactivated with Legends on/off (see figure 39).
Figure 39: Defining the legend
6 Plot 45
6.6.1 Legend Frame on/off
A frame is drawn around the legend.
6.6.2 Legend Background on/off
If this is set to off the legend will be transparent, i.e. the measuredvalues and grid lines are visible right through the measurementwindow.
If the legend background is set to on, all lines lying behind thelegend are hidden.
6.6.3 Legend Position x/y
Position of the legend in the range 0-1. This is the position of thetop left corner on the virtual sheet.
6.6.4 Char Size
Font size of the legend in the range 0.5-2.0.
6.6.5 Legend Text
An input window is available here for each selected measurementcurve. On the screen you will see in each case a short line in thecolour of your measurement curve, with the text next to it. This textis by default the file name of your measurement, but if you want toenter something different here, you can overwrite this name.
6.7 Text
As well as the legend, you can define two further text sections (fig.40).
6.7.1 String on/off
This option activates or deactivates the text string.
6.7.2 Position x / Position y
6.7.3 Char Size
As with the legend text, here you can define the position and thefont size.
6.7.4 Text Colour
Here you define the colour of the additional text as well as line 1or 2 of the actual comment.
6 Plot 46
Figure 40: Entering additional text and arrows.
6.8 Lines/Arrows
To mark specific places in your measurement curve, you can drawin two lines or arrows.
Altogether there are two input masks available for two lines or ar-rows.
The start and end positions of the line are defined in turn by a pairof numbers from the range 0-1.
6.8.1 Arrow Style
Here you can select whether the line is to have an arrow or whichform this arrow will take.
6.8.2 Arrow Size
Here you enter the size of the line/arrow.
6.8.3 Colour
Here you select the colour of the line/arrow.
6.9 Text of the header
Above and below the drawing area you can output an additionaltext. This text is only displayed when you print via the HTMLbrowser - not when you output the drawing as a Postscript or PDFfile.
6 Plot 47
6.9.1 Text on/off
Activates or deactivates the text lines.
6.9.2 Char Size
As with the legend text, here you can define the font size from therange 0-2.
6.9.3 Text Colour
Here you define the colour of the additional text.
6.10 Footnote text
Above and below the drawing area you can output an additionaltext. This text is only displayed when you print via the HTMLbrowser - not when you output the drawing as a Postscript or PDFfile.
6.10.1 Text on/off
Activates or deactivates the text lines.
6.10.2 Char Size
As with the legend text, here you can define the font size from therange 0-2.
6.10.3 Text Colour
Here you define the colour of the additional text.
6.11 Creating the drawing
When you have finished making your settings, you can display thedrawing by clicking the Draw button at the beginning of the inputmask.
If you still need to make corrections to the drawing, you can branchback to the appropriate field of the input mask by clicking either theblue ’up’ arrow or the relevant area in the symbolic graphic. If youare satisfied with all the settings, you can print the graphic us-ing the print function in your Internet browser, provided that in theColour/Output Type input box (section 6.2.6) you have selectedthe option Colour or JPEG, i.e. the first or second menu item. Ifyou have selected the option PDF/Acrobat, depending on whichInternet browser you are using, a small button labeled Picture (orsimilar) will appear. If you click this, the Acrobat Reader programstarts automatically and the graphic is displayed in this window.Use the Acrobat Reader print function to print the graphic. If you
6 Plot 48
are using Windows and you right-click the graphic, you will be of-fered options for exporting it into other programs or editing it fur-ther, e.g. Open Graphic in Microsoft Word.
If you are happy with the way your drawing looks, you can go backto the input mask and save all the settings you made so that youcan call them up again later. You do this right at the top of theinput mask in the Display parameter file field. Enter there a namefor your setting configuration and then call up the drawing again.A display parameter file with the name you entered will be createdautomatically.
If you now want to display further measured data in the same form,all you need to do is select your measurement files and then callup the assigned display parameter file under the menu item Plot.All settings will then already be made automatically in the inputmask, and you need only click the Draw button to display the mea-surements in your chosen form.
Figure 41 shows a display in the browser.
Figure 41: Graphic in an Internet browser
7 Data 49
7 Data
This menu item contains all operations which involve exporting theViskomat data into other programs or onto other systems.
7.1 XCel
The Viskomat NT program offers a new interface to Microsoft’s Ex-cel spreadsheet program. This means that data can be importeddirectly into this program. When you click the menu item Xcel, thefile selection mask described in section 4.2 is displayed.
If you click the OK button, all existing files will be listed in a tableshowing their file name and a comment. The first column of thetable also contains a button for each. You select the files you wantby clicking them.
Another input mask appears (see figure 42). Above the table arefour selection fields, via which you can define which data of yourmeasurement results is displayed in the first, second and thirdcolumns of the Excel sheet, e.g. time in minutes, torque in New-ton millimeters, temperature in degrees Celsius or revolutions perminute in rpm.
Figure 42: Exporting to Excel, selecting column content
A fifth selection field allows you to define which decimal separatoris used. Please use a decimal point for all language versions of
7 Data 50
Excel other than German, which uses a comma. If this field is notset correctly, the figures may be displayed incorrectly in Excel.
When all options have been set correctly, click the Excel files but-ton. All measurement files you have selected are displayed withtheir file name ending in .xls. If you now click one of these filesnames, Excel will open automatically and the data will be exportedinto your worksheet (provided Excel is installed on your system).If Excel is not installed on your system, you can save these fileson your local desktop. This option is normally offered to you au-tomatically by the Windows operating system. You can select thisfunction manually from most Internet browsers by clicking the filename with the right mouse button. Figure 43 shows again howExcel is opened via this option. The Excel export also provides aconvenient way of saving the data locally on your system. Simplyselect the function File - Save As... in Excel. If you are working di-rectly on the Viskomat NT OpenOffice instead of Excel is openedif you double-click on a *.xls file. OpenOffice is free, available forWindows, Linux and other systems and at least as powerfull asother so called standard programms. Try it and you will enjoy it..
Figure 43: Excel opens automatically with the selected measureddata
7 Data 51
7.2 VSC
Under this menu item you can create the file format of the Viskoprogram for the Viskomat PC. This allows you to load measure-ments from the Viskomat NT into the Visko program for the Visko-mat PC and to compare the data. When you click this item, thefamiliar file selection dialog opens. Click OK again to display a listof your measured data.
In the second section of this mask you will see the options Numberof values and Minutes (figure 44).
Figure 44: Export of the data files
The maximum number of measured values on the Viskomat PCwas limited to 1024. On the Viskomat NT, however, you can use100,000 values and more. If you still want to evaluate Viskomat NTmeasurements with the Viskomat PC program, you can reduce thenumber of measured values here to various quantities between 10and 1023. This is done through interpolation. Select the numberof values you want. In the Minutes field you can reduce your mea-surement to the desired number of measured minutes. You selectthe measurement files by clicking in the first column of your filelist.
When you click the VSC files button, you get a list of the files youselected with a file name ending in .vsc. If you select one of these
8 Viskomat 52
files, the Windows operating system automatically opens a file se-lection dialog. You can now save this file on your local control PC.It is best to save it in the data directory of the Visko program. Thenwhen you start the Visko program on your evaluation PC, you canload the measurement file like a Viskomat PC file.
You can also choose the txt-file format. Thats a convenient textfile where all columns of measurement data are seperated by atabular sign. This format may be imported by the most softwarelike Word, Origin, Excel, and the most database programs likeAccess or MySQL.
7.3 Database
As described under Start (section 5.1), you can assign a commentto each measurement file. This comment can also be entered ormodified at a later stage. This is done via the Database menuitem.
When you click Data - Database, you get the familiar data selec-tion menu.
Click OK to get a list of your measured data. Now select the mea-surement files you want to edit by clicking in the first column of thefile list. When you click the Edit button, an input window opens foreach selected measurement file, in which you can edit the com-ment for the file. The comments are stored in a special databasefile, not in the measurement files. If you export a *.vsc ore *.txt filethe comment is linked to the end of the measurement datasets.
The Save button saves the comment, with Delete you can deletethe whole comment, and the Home button returns you to the mainmenu without saving.
7.4 Datasets
This allows you to copy the measurement files (file name suffix.dat) to your local evaluation PC. When you select this menu itema list of your measurement files is then displayed, including sizeand creation date. Depending on your operating system, you cannow drag and drop these files onto your desktop or into a folderore click with the right mouse button on the link and choose savelink as.. (see figure 44).
8 Viskomat
Starting and stopping the Viskomat. This is now directly done atthe Viskomat. For security reasons a remote start or shutdown isno longer allowed.
9 Online display 53
9 Online display
During measuring, a graphical and a numerical online display canbe shown in the browser of the Viskomat NT. The display com-prises different optional graphics in the left part of the screen anda number of numerical displays in the right part of the screen.
This onlien display may be shown in the browser on the localViskomat computer and also in any remote browser. This fea-ture requests a browser like Firefox, Chrome etc. with a softwarerelease not older then 2014.
The display can be shown in the actual browser tab, or you mayopen a new tab to have a bigger display. You may shore differentonline displays in several tabs for example torque over time and inanother tab torque over speed. Figure 45 shows a screenshot.
Figure 45: The online display in the browser in a new tab
9.1 Configuration in the Controlbar
The selection of the requested graph and the configuration is donein the control bar at the button of the online screen. You maystart and stop the display, select the graph type, zoom the display,select the language etc. Figure 46 explains the options.
9.2 Infos in the Header
The header shows the actual x and y axis, the name of the actualprofile and in big characters the name of the actual measurementfile. You may see an example at figure 47
9 Online display 54
Figure 46: Settings for the online display
Figure 47: Information in the title of the online graph
9.3 The sidebar
On the right bar of the online graphic you see in parallel somenumerical online informations. If the measurement runs you maysee the actaul measurement time, if the Viskomat is not active yousee the actual time. All other infos are explained in figure 48
9.4 Multigraph
The Multigraph shows, during the measurement, 1..8 different graphs(fig. 49). For example speed vs. time, temperature vs. time ortorque vs. speed (fig. 50). You may select the type of graph withthe buttons in the lower right corner of the screen. At least onegraph is shown, so its not possible to de-select all graphs. Withthe flag symbol you can switch the language of the user interfacebetween German and English. On the lower left corner is a buttonto select the desired time range. The name of the actual measur-ment file is shown above the graphs.
9 Online display 55
Measurement time (if test is running)
or actual time
Measurement time (if test is running)
or actual time
Measurement time in %of the total time
Measurement time in %of the total time
statusstatus
Speed in rev. per minuteSpeed in rev. per minute
Actual torque in NmmActual torque in Nmm
Actual temperature in °C
Actual temperature in °C
Figure 48: Information in the title of the online graph
Figure 49: Multigraph with 8 graphs.
10 System 56
Figure 50: Multigraph with 4 graphs.
10 System
This is where all the basic system settings are made.
Warning: Some changes do not take effect until you restart theViskomat.
You save the values you have set by clicking Submit .
10.1 Setup
Here you can make some basic settings for the Viskomat NT. Thetop part of the input mask (see figure 51) contains the height set-tings, in which you define how far the probe is to be inserted intothe sample container in increments of 0.025 mm.Warning:
Usually you should not change the factory settings here. If thevalue you enter is too high, the measuring head could be insertedtoo far, which could damage the probe. Please inform Schleibingerbefore you make any changes!
In the second section of the input mask, however, you can makechanges without problems.
The following can be set:
10.1.1 Height Adjust
For each type of probe you may adjust the insertion depth of theprobe. The measurement unit is in mm from the reference point(some mm below the top position). In the 2nd column of the inputmask you may define from which position the speed of the lift willbe reduced. The insertion depth is defined for each probe. For
10 System 57
Figure 51: System settings
the mortar probe, the cement paste probe, the modified cementpaste probe and the basket probe the values are the same. Thetau factor and gamma factor are defining the the calculation fromtorque and speed to shear rate and shear stress. This is onlyused in the plot menu for a right display of γ and τ . For the basketprobe please set the tau factor to the value shown in the calibrationcertificate of the basket probe. This factor is called τ and is usually1.018. The gamma factor is called γ̇ and is usually 0.611.
Don’t change the insertion depth! By changing the insertionAttention!depth the probe may be crashed by the lift and damadge the sen-sor.
10.1.2 Sampling rate
Here you define the interval at which the Viskomat is to recordmeasured data. The following settings are available: 5ms, 10ms,50ms, 0.1 sec, 1 sec, 4 sec, 10 sec, 1 min
The setting 4 sec, for example, means that a value is entered inthe measurement file every four seconds. This setting also cor-responds to the setting on the Viskomat PC. Faster settings, e.g.0.1 sec or 1 sec, create larger measurement files but they alsoincrease the resolution.
10.1.3 Averaging Rate
After each measurement a 2nd datafile is created. Its name isthe main file name with an extension meanval. This file contains
10 System 58
smoothed data. If the sample rate is 0.1s and the averaging rateis 4s, each value in the new file is the mean value of the last4s/0.1s = 40 values.
10.1.4 Filter cut-off frequency
The measuring-head electronics of the Viskomat NT contain a dig-ital low-pass filter. This means that the recorded torque values ofthe measuring head are filtered to eliminate photoelectric noiselevels or high-frequency vibrations. In the menu the cut-off fre-quency of this filter is set here. You can choose from the values1Hz, 10 Hz, 100 Hz and 1000 Hz. If possible, you should selecta relatively small value to ensure that your measurement resultsare as smooth as possible. Even at a setting of 1 Hz, very fastchanges in the torque can be filtered out. For torque-controlledoperation you should choose settings above 1 Hz. At least 10 Hzor 100 Hz cut-off frequency is recommended here.
A sampling rate of 0.1 sec and a filter cut-off frequency of 1 Hzis not a good combination, because with a setting of 1Hz cut-offfrequency a value is only recorded every 0.5 seconds.
10.1.5 Max. torque
Here you set the the maximum torque at which the Viskomat auto-matically aborts the measurement and withdraws the measuringhead from the sample You can choose from the values 50 Nmm,100 Nmm, 200 Nmm, 300 Nmm and 1000 Nmm. At 1000 Nmm,the measuring head of the Viskomat NT is already significantlyoverloaded, so this setting should not normally be selected. TheViskomat XL has a range up to 10.000 Nmm.
Also different torque rates may be available in the menu on cus-tomers demand.
10.1.6 Vessel Start Speed
Sometimes it may be useful already to turn the vessel during theprobe is diving in. This start-speed is set here. Counter clockwisespeeds are negative.
10.1.7 Shear-Stress Factor
In the shear stress controlled mode, the speed is controlled bythe required torque, and therefore depending on the material stiff-ness. For very fluid material take a high factor here for very stiffmaterials a low factor. Please keep in mind that in the shear stresscontrolled mode the maximum speed is limited to about 10 rpm.
11 Home 59
10.1.8 Measurement Range
The Viskomat NT (from 2010) has to measurement ranges. Thefirst range is from 0 . . . 250 Nmm, the 2nd range from 0 . . . 500Nmm. If you change the measurement range you have to reloadthe profile, before the next measurement. For the Viskomat XLalso 3.000 Nmm and 10.000 Nmm ranges are available. Pleasedon’t select a higher range then 500 Nmm for the Viskomat NT!
10.1.9 Temp. measurement yes/no
The standard probe for cement paste or mortar has an integratedtemperature sensor, which also records the temperature of thesample during measuring. Some other measuring geometries donot have an integrated temperature sensor, so temperature mea-surement can be switched off. This is mandatory for shear stresscontrolled measuring.
10.2 Addresses
This subsection is only valid for systems produced before June,2006
As mentioned in the introductory chapter, the Viskomat NT is gov-erned by the so-called Internet Protocol. Every computer in theInternet has a unique number, which consists of a group of fourthree-digit numbers. The Viskomat normally comes with a presetInternet address.
This address can be adjusted to the requirements of your networkin this menu (see figure 11). Like the Viskomat NT, the controlPC also has an Internet address, which can likewise be modifiedhere. As well as the numeric Internet address, each Viskomat NThas a system name, which usually comprises the three letters vntand a two-digit number. The Addresses menu shows the currentInternet addresses and the current Viskomat name, which you canchange by entering new addresses for the Viskomat NT and thecontrol PC.
Please consult your network administrator or Schleibinger beforechanging these settings.
11 Home
Home returns you to the Viskomat main menu.
12 Help
Clicking Help opens the Online Help, which contains the completemanual for the Viskomat.
13 Probe Calibration 60
13 Probe Calibration
13.1 Viskomat NT
The Viskomat NT is delivered with 2 standard probes:
The so called mortar probe, designed for mortar and cement pastewith a maximum aggregate size from 0..2 mm (fig. 52).
The so called paste probe designed for a aggregate size from0..0.5 mm (fig. 53).
Figure 52: Geometry and dimensions of the mortar-probe forViskomat NT.
Figure 53: Geometry and dimensions of the paste-probe for Visko-mat NT.
13 Probe Calibration 61
Unfortunately classical rheometer geometries like come plate orcylinder-cylinder systems doesn’t work with common building ma-terials like mortar, or fresh concrete. Therefore Schleibinger hasdeveloped a different probe design to avoid segregation and sedi-mentation of the material during the measurement.
The disadvantage of this probes is, that the geometry of the com-mon plate-plate can’t be applicated onto this shape. The flowaround this probes is laminar but 3-dimensional. So the shearstress vs. shear rate is an unknown but linear function.
With a Newtonian fluid with a known viscosity we may calibrateboth probes. We used a silicon oil with a viscosity of 12500 mPa*sat 25.0C, see figure 54. The calibration coefficients are shown intable 1.
Table 1: Calibration constants for the standard Viskomat NTprobes
Probe Type calib. const. cpmortar-probe 12.5 / 0.447 = 27.96paste-probe 12.5 / 4.19 = 2.98modified paste-probe 12.5 / 1.96 = 6.38
0.0 50.0 100.0 150.0 200.0
v / Upm
0
10
20
30
40
50
60
70
Mom
ent /
Nm
m
2014_Aug_8_Fri_11_27_43_oeltest2.dat
2014_Aug_8_Fri_11_44_57_oeltest3.dat h : 0.500 g : 0.042 korr :0.99979
2014_Aug_8_Fri_11_44_57_oeltest3.dat h : -0.000 g : 25.213 korr :-0.04576
Viskomat NT Messung Abgleich Aug 2014 201210874
Figure 54: Flowcurve of a silicon oil with 12.7 Pa*s measuredwith the mortar-probe of the Viskomat NT at 25.2C
With the plot function you may display the torque vs. speed. With ainterpolation you may calculate a viscosity as described in chapter6.4.10. The viscosity factor v is calculated in Nmm*min. To cal-culate the viscosity of an unknown material multiply the v by theconstants cp shown in table 1.
The viscosity η is v multiplied by cp: η = cpv
For non-Newtonian fluids this calibration can’t be done in a generalway. There is no Bingham standard fluid on the market.
13 Probe Calibration 62
13.2 The Basket Probe
The basket probe designed by R. Vogel, Weimar, Germany. is adouble gap probe with a special designed bop. The surface of theprobe is like gasket to avoid wall slippage. The material insideand outside the probe is gluing together through the meshes ofthe gasket.
N is the speed of the viskomat NT in rpm, T is the measuredtorque in Nmm. The calibration constants are then given as fol-lows:
τ = η γ̇ =T
D2πHck
τ =T
1, 0215 · 1, 028= 0, 9523 · T [Pa]
[Nmm]
ck = 1, 028
γ̇ = 0, 592N[min]
[s]
Figure 55: Geometry and dimensions of the basket probe for theviskomat NT.
13 Probe Calibration 63
13.3 Viskomat XL
The Viskomat XL is delivered with 2 standard probes:
The so called circular or fishbone shaped probe, designed forfresh concrete and mortar with a maximum aggregate size from4..16 mm (fig. 56). The fishbone probe may also be used for fineraggregates.
The so called windows or paste probe designed for a aggregatesize from 0..4 mm (fig. 57).
Unfortunately classical rheometer geometries like come plate orcylinder-cylinder systems doesn’t work with common building ma-terials like mortar, or fresh concrete. Therefore Schleibinger hasdeveloped a different probe design to avoid segregation and sedi-mentation of the material during the measurement.
The disadvantage of this probes is, that the geometry of the com-mon plate-plate can’t be applicate onto this shape. The flow aroundthis probes is laminar but 3-dimensional. So the shear stress vs.shear rate is an unknown but linear function.
With a Newtonian fluid with a known viscosity we may calibrateboth probes. We used a silicon oil with a viscosity of 12500 mPa*sat 25.0C, see figure 58 and 59. The calibration coefficients areshown in tabular 2.
With the plot function you may display the torque vs. speed. With ainterpolation you may calculate a viscosity as described in chapter6.4.10. The viscosity-factor v is calculated in Nmm*min. To cal-culate the viscosity of an unknown material multiply the v by theconstants cp shown in tabular 2.
The viscosity η is v multiplied by cp: η = cpv
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
A A
B B
C C
D D
E E
F F
1
A2
Zirkularpaddel
vgr-817-11-09
Änderungen
Gezeichnet
Kontrolliert
Norm
Datum Name01.12.2009 Teubert
Allgemein-
toleranzen
DIN 2768-f
Schleibinger GeräteBuchbach
Material: Geschweißtes Aluminum-6061
Gewicht: 0,219 kg
C:\CAD-Arbeitsbereich\CAD Daten\viskomat gr\(8) paddel\vgr-817-Zusammenbau-Paddel-Circular.idw
Projekt:
Oberfläche:
30.09.2015
Maßstab Erstansicht:
viskomat XL
unbemasste Werkstück-
kanten DIN 6784
-0,1-0,2
00,2
7723
0
5 H7 (- 0,000,01 )+
5Ø
37,3
60,5
11,8
12
R99
R99
5
146
27
52102
Figure 56: Geometry and dimensions of the fishbone probe, de-livered with the Viskomat XL
13 Probe Calibration 64
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
A A
B B
C C
D D
E E
F F
1
A2
Montage Betonpaddel
vgr-811-06-11
Änderungen
Gezeichnet
Kontrolliert
Norm
Datum Name18.09.2009 Teubert
Allgemein-
toleranzen
DIN 2768-f
Schleibinger GeräteBuchbach
Material:
Gewicht: 0,370 kg
C:\CAD-Arbeitsbereich\CAD Daten\viskomat gr\(8) paddel\vgr-811-zusammenbau-betonpaddel.idw
Projekt:
Oberfläche:
30.09.2015
Maßstab Erstansicht:
viskomat XL
06/11 Winkel der Flunken 45°, wg Abstr.
unbemasste Werkstück-
kanten DIN 6784
-0,1-0,2
00,2
237
30
5
Montage mit Loctite 603
Montage mit Petec Gewindedichtung
Montage mit Petec Gewindedichtung
Montage mit Petec Gewindedichtung
(7)
(109)
128
128
Figure 57: Geometry and dimensions of the window- orpasteprobe, delivered with the Viskomat XL
Table 2: Calibration constants for both Viskomat XL probesProbe Type calib. const. cpfishbone 12.5 / 4.74 = 2.62window 12.5 / 14.23 = 0.88
For non-Newtonian fluids this calibration can’t be done in a generalway. There is no Bingham standard fluid on the market.
13 Probe Calibration 65
0.0 10.0 20.0 30.0 40.0 50.0
v /rpm
0.0
50.0
100.0
150.0
200.0
250.0
300.0
Tor
que
/ Nm
m
2015_Oct_5_Mon_15_51_23_fishbone_probe4.dat
2015_Oct_5_Mon_15_51_23_fishbone_probe4.dat h : 4.741 g : 0.010 korr :0.99981
2015_Oct_5_Mon_15_51_23_fishbone_probe4.dat h : -0.010 g : 25.099 korr :-0.99306
Vskomat NT Concrete / Fishbone Probe 12.5 Pa*s
Figure 58: Flowcurve of a silicon oil with 12.5 Pa*s measuredwith the fishbone probe of the Viskomat XL
0.0 10.0 20.0 30.0 40.0 50.0
v /rpm
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
Tor
que
/ Nm
m
2015_Oct_5_Mon_17_13_46_windowprobe1.dat
2015_Oct_5_Mon_17_13_46_windowprobe1.dat h : 14.225 g : 2.282 korr :0.99879
2015_Oct_5_Mon_17_13_46_windowprobe1.dat h : 0.006 g : 24.529 korr :0.99095
Vskomat NT Paste / Window Probe 12.5 Pa*s
Figure 59: Flowcurve of a silicon oil with 12.5 Pa*s measured withthe window probe of the Viskomat XL
13 Probe Calibration 66
13.4 Non Newtonian Fluids
Measuring non Newtonian fluids is still a demanding task, evenwith standard geometries like cylinder-cylinder (cc) or cone-plate(cp) systems.
With plate-plate (pp) systems its not possible because there is nodefined shear rate over the diameter of the system.
Even with cc or cp systems you must be sure that the so calledBingham condition is fulfilled, meaning that the shear rate in thewhole gap is high enough to shear the entire gap. The secondsevere condition is the so called wall slippage effect. Inhomo-geneous suspensions like mortar, fresh concrete or paste, aremaking are producing a thin film of water or water and very fineparticles in the interface layer between the suspension and therheometer probe surface, usually a smooth steel surface. A roughor ripped surface doesn’t avoid this effect.
One special probe is the so called basket system (bs) which triesto minimize the wall friction by using a kind of mesh structure.
The NIST is juts developing a calibration fluid for paste and mortarand even the fresh concrete. Please check the website Link to theNIST
Several authors tried a calibration for the mortar or paste probe ofthe Viskomat NT. For the the mortar probe Flatt, Larosa and Rous-sel [1] tested in 2006 a polymer solution in a cp system against theViskomat NT mortar-probe. The found the calibration coefficientsshown in tabular 3.
Table 3: Calibration constants from Flatt et.al. for the mortar-probe for the Viskomat NT.
Shear rate K s−1/(min−1) 0.329 0.335 0.332Shear stress K/G Pa/(Nmm) 9.77 9.95 9.86Viscosity 1/G = cp Pa(s)/(Nmm)(min) 29.7 29.7 29.7
Banfill [2] did a similar research project already in 1990 for theViscocorder which has the same geometry as the Viskomat NT.He found the results shown in tabular 4. He found a factor Kfor calculating the shear rate γ̇ from the speed in rpm from theViskomat which was only the half the the results from Flatt et. al.The factor K/G which is calculting the yield value τ0 in Pa fromthe Viskomat result in Nmm is in the same range then the resultsfrom Flatt. The conversion factor for the viscosity η is higher thenthen the factor calculated by Flatt.
The calibration from Flatt et. all may be right. The results fromBanfill are in contradiction with several hundreds of measurementswe did in our lab. You may easily check this with an calibration oil.
13 Probe Calibration 67
Table 4: Calibration constants from Banfill for the mortar-probefor the Viskomat NT. Attention: cp seems to be wrong by factor 2
Shear rate K s−1/min−1 0.166Shear stress K/G Pa/(Nmm) 7.9Viscosity 1/G = cp (Pa ∗ s)/(Nmm)(min) 46.8
To get the values for γ̇ and τ in the graphic please check if theright values for the tau factor and the etha factor are set in theSystem Setup (see chapter 10.1.1 ). So following Flatt the taufactor should be 9.95 the gamma factor 0.33. For paste probethe paste probe the gamma factor is about 10 times higher, sowe recommend a factor of 3.3 . For the tau facor now calibrationfactor is known yet. We recommend a factor of about 10.
For the Viskomat XL no valid calibration constants for non-Newtonianfluids are known yet.
13.5 The Vane Probe
The theoretical idea behind the vane probe is to approach a cylin-der geometry without having wall slippage effects. In literaturevane probes with 2..8 blades are described. Figure 60 shows thevane probe for the Viskomat XL.
Figure 60: Vaneprobefor the Viskomat XL. The basket is an inletfor the vessel to minimize wall slippage.
13 Probe Calibration 68
Its obvious that a 6 blade vane is more a cylinder then a 4 plateone. If you look into the paper of Barnes et. al. [3] you may seethat they introduce two ”Bulgarian constants” for each number ofplates. This factors are (1, 0.66) for 2 plates, (1.51, 1.2) for 4plates and (1.66, 1.56) for 6 plates. But if you look at the equation2 of Barnes (equivalent to equation 9 of Keentok [4]), the numberof plates has no influence in measuring of the yield stress.
So τ0 =M/[(2πa3) ∗ (l/a+ 2/3)]
where M is the measured torque, a is the radius and l the lengthof the blades.
For the Viskomat NT the probe has a radius a of 20 mm and alength l of 60 mm.
For the Viskomat XL we have the following dimensions:
l/a = 69mm/34.5mm = 2
so
τ0 =M/[2πa3 ∗ 8/3]
depends only in the radius of the vane probe (curious, isn’t it?)
Calculated with the XL geometry size:
τ0 =M/[2π0.03453 ∗ 8/3]
τ0 = 1453.43 ∗M
if M is measured in N m ore
τ0 = 1.45343 ∗M
if M is measured in N mm result is in Pa
For the viscosity
M̃ = Al̃ +B
with
M̃ =M/(2πηa3ω) and
l̃ = l/a = 2 again
where ω = U [60/(2π)] and U is the speed in rpm
M̃2πηa3 ω =M (1)η =M/(M̃2πa3 ω) (2)
η =M/[(M̃2πa3 U 60)/(2π)] (3)η =M/[M̃a3 U 60] (4)
For
l/a = 2⇒ l̃ = 2⇒ (5)M̃ = 2A+B (6)
References 69
so for 4 blades M̃ = 2 ∗ 1.51 + 1.2 = 4.22
and for 6 blades M̃ = 2 ∗ 1.66 + 1.56 = 4.88
so for 6 blades:
η =M/(4.88 a3U60) (7)η =M/(292.8 a3U) (8)
a = 69/2mm = 34.5mm = 0.0345m⇒ a3 = 41.0636 10−6m3 ⇒ (9)η =M/0.012023 = (M ∗ 83.17)/U [Nm/(1/min)](10)
η [Pa s] = 0.08317(M/U) [Nmmmin](11)
References
[1] Linking yield stress measurements: Spread test versus Visko-mat, Robert J. Flatt a, Domenico Larosa a, Nicolas Rousselb, a Sika Technology AG, CH-8048 Zrich, Switzerland, b Lab-oratoire Central des Ponts et Chausse’es, Paris 75732 ParisCedex 15, France, Cement and Concrete Research 36 (2006)99 - 109.
[2] Use of the ViscoCorder to study the rheology of fresh mortar P.F. G. Banfill, University of Liverpool, The Magazine of ConcreteResearch, 1990, 42, No. 153, Dec., 213-221.
[3] Rotating Vane Rheometry – A Review, Howard AnthonyBarnes and Quoc Dzuy Nguyen, Journal of Non-NewtonianFluid Mechanics, Volume 98, No. 1,2001, page 1 - 14.
[4] The Measurement of the Yield Stress of Liquids, M. Keentok,Rheology Acta 21, page 325-332, 1982.
13.6 Comparing the Vane and the Mortar Probe
In the following graphs you may see a comparison of the mortarprobe and the vane probe of the viskomat NT.
The profile was simply an acceleration from 0 to 120 rpm in oneminute and going back to 0 in another minute.
On the graph you see the speed in rpm on the x-axis and themeasured torque in Nmm on the y-axis.
The first measurement (figure 61) shows the measurement of asilicone oil of 12720 Pa*s at 24C.
The second measurement in figure 62 shows the same for a kindof Bingham fluid. We used a common ultrasonic hydrogel whichwas widely used at the doctors. This hydrogels are based oncarbomers and their derivatives. Carbomers are polymers of theacrylic acid (polyacrylates) whose salts can bind enormous amountsof water.
References 70
0.00 50.00 100.00 150.00 200.00
v / Upm
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
Mom
ent / N
mm
2016_Nov_20_Sun_17_12_55_500Nmm_oiltest_tu_wien.dat Mortar Probe
2016_Nov_20_Sun_17_46_55_oiltest_vane.dat Vane Probe dia. 40 mm / height 60 mm / 6 blades
Viskomat NT
2016_16469 TU Wien
Figure 61: Comparison of the vane probe and the mortar probewith silicon oil as Newtonian fluid.
0.00 50.00 100.00 150.00 200.00
v / Upm
0.00
10.00
20.00
30.00
40.00
Mom
ent / N
mm
2016_Nov_20_Sun_18_08_28_mortar_probe_US_gel.dat Mortar Probe
2016_Nov_20_Sun_18_24_32_vane_US_gel.dat Vane Probe
Viskomat NT
2016_16469 TU Wien
Figure 62: Comparison of the vane probe and the mortar probewith a Bingham fluid.
14 The Chiller UKH 67.2 71
14 The Chiller UKH 67.2
For temperature control you may use the Chiller UKH 67.2. Pleaseplace the chiller near the Viskomat NT. Best position is below theViskomat, for example below the table where the Viskomat stands.The chiller has a built in fan and needs open air circulation. Sodon’t place it in a closed cupboard or cabinet.
There is a 3 m hose included as well as some cable ties. Cut thehose in two parts. Make the hoses a short as possible to avoidthermal losses. Connect the chiller outlet (see figure 64) with thevalve at the upper tube as shown in figure 12. Connect the chillerinlet with the valve at the lower tube as shown in figure 12.
Fill the outer vessel of the Viskomat with about 0.5 l of normaltap water. Take a funnel, open the ULK filling and fill about 1 l ofnormal tap water into the chiller. If you like to rum at temperaturesbelow 10◦C add. some antifreeze as used for your car engine.
Close the lid of the filler again.
Open the valves at the chiller inlet and at the Viskomat (fig. 12).Start the the chiller with the red button on the front panel.
If the outer Viskomat vessel is running empty fill water in again sothat the outlet and the is immersed with water. Fill up to about halfthe vessel. If there is an error message of the chiller controller,switch off the chiller , tilt the whole chiller in all axis about 30◦ toremove remaining air in the circulation, and start the chiller again.
Figure 63: Chiller outlet and filler.
14 The Chiller UKH 67.2 72
Figure 64: Chiller inlet.
Figure 65: Chiller on/off button (red), on/off button for the coolingmachine (green) and the controller.
To program the set temperature please use the arrow buttons atthe controller as shown in figure 65. Please set now temperaturesbelow +5◦C and for safety reasons no temperatures above +65◦C.Use appropriate handkerchiefs for handling the cool or hot vessel.
If the circulation is running with air bubbles please activate thecooling machine with the green button.
15 Packing List: 73
15 Packing List:
part quantity okViskomat 1Electronic 1Connectin cables 3Probe cable 1 +Mortar probe 1 +Paste probe 1 +mod. Paste probeOuter VesselValves with screws 2Vessel 1 +TFT Display 1Keyboard 1MouseMousepad 1Scraper 1+Allen keyUser Manual 1Network cable 1Multiple socketMains wiresCirculating unitPolysiloxane tubecable fasteners 5Safety guard for the Viskomat (XL)Delivery Note 1
List of Figures 74
List of Figures
1 Rheometers Viskomat NT and Viskomat XL. . . . . . 6
2 Connectors on the backside of the Viskomat elec-tronic . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3 Connectors on Viskomat NT . . . . . . . . . . . . . . 8
4 Connectors on the backside of the Viskomat XL.Since 2011 the lift connector is beneath the motorconnector. . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Connector for the Viskomat XL lift unit, used since2010 . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Connector for the lift unit, used since 2011 . . . . . . 10
7 Power Switch, USB ports, status LED, version 1 . . . 11
8 Power Switch, USB ports, status LED, version 2 . . . 11
9 Alert Window popping up if the motor power supplyis off . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
10 Fastening the probe into the Viskomat NT. . . . . . . 13
11 Installing the sample container. . . . . . . . . . . . . 13
12 Tubes in the right position . . . . . . . . . . . . . . . 14
13 Tubes in the maintenance position, you may nowremove the double wall container. . . . . . . . . . . 14
14 The safety guard of the viskomat XL in the working/ normal position (left) and in the opened position(right). . . . . . . . . . . . . . . . . . . . . . . . . . . 16
15 An alert window shows that the safety guard is open.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
16 An alert window shows that the motor power supplyis off. Please close the safety guard and press okto restart the motor power supply. . . . . . . . . . . 17
17 The tubes of the viskomat XL in normal operatingposition . . . . . . . . . . . . . . . . . . . . . . . . . 17
18 Mounting the probe into the Viskomat XL . . . . . . 18
19 Installing the sample container for the Viskomat XL. 19
20 Mounting the outer vessel of the Viskomat XL. . . . 19
21 Network connection of the Viskomat. . . . . . . . . . 21
22 Start page in your browser (here Mozilla Firefox) . . 22
23 Main menu for operating the Viskomat NT from withinthe Internet browser . . . . . . . . . . . . . . . . . . 23
24 Enter Profile mask . . . . . . . . . . . . . . . . . . . 26
List of Figures 75
25 Step profile as entered in figure 24 . . . . . . . . . . 26
26 Enter profile as ramps . . . . . . . . . . . . . . . . . 27
27 Measurement curve according to ramp profile asentered in figure 26. . . . . . . . . . . . . . . . . . . 27
28 File selection mask as used at several points/placesin the program . . . . . . . . . . . . . . . . . . . . . 29
29 Successful profile download. . . . . . . . . . . . . . 29
30 Measurement Start by entering the file name andcomment . . . . . . . . . . . . . . . . . . . . . . . . 31
31 Clickable or context-sensitive map . . . . . . . . . . 32
32 Input mask Plot, Plot area . . . . . . . . . . . . . . . 34
33 Input fields for the x-axis . . . . . . . . . . . . . . . . 36
34 Y-Axis area . . . . . . . . . . . . . . . . . . . . . . . 38
35 Vessel angle over time, and resulting force on thepaste probe. Material wallpaper paste. Instrument:Viskomat XL . . . . . . . . . . . . . . . . . . . . . . 40
36 Torque over angle. A typical Lissajous figure. Ma-terial wallpaper paste. Instrument: Viskomat XL . . . 41
37 Calculation G′ and G′′ from the ellipse . . . . . . . . 41
38 G′ and G′′ over the frequency. Material wallpaperpaste. Instrument: Viskomat XL . . . . . . . . . . . . 42
39 Defining the legend . . . . . . . . . . . . . . . . . . . 44
40 Entering additional text and arrows. . . . . . . . . . . 46
41 Graphic in an Internet browser . . . . . . . . . . . . 48
42 Exporting to Excel, selecting column content . . . . 49
43 Excel opens automatically with the selected mea-sured data . . . . . . . . . . . . . . . . . . . . . . . . 50
44 Export of the data files . . . . . . . . . . . . . . . . . 51
45 The online display in the browser in a new tab . . . . 53
46 Settings for the online display . . . . . . . . . . . . . 54
47 Information in the title of the online graph . . . . . . 54
48 Information in the title of the online graph . . . . . . 55
49 Multigraph with 8 graphs. . . . . . . . . . . . . . . . 55
50 Multigraph with 4 graphs. . . . . . . . . . . . . . . . 56
51 System settings . . . . . . . . . . . . . . . . . . . . . 57
52 Geometry and dimensions of the mortar-probe forViskomat NT. . . . . . . . . . . . . . . . . . . . . . . 60
List of Figures 76
53 Geometry and dimensions of the paste-probe forViskomat NT. . . . . . . . . . . . . . . . . . . . . . . 60
54 Flowcurve of a silicon oil with 12.7 Pa*s measuredwith the mortar-probe of the Viskomat NT at 25.2C . 61
55 Geometry and dimensions of the basket probe forthe viskomat NT. . . . . . . . . . . . . . . . . . . . . 62
56 Geometry and dimensions of the fishbone probe,delivered with the Viskomat XL . . . . . . . . . . . . 63
57 Geometry and dimensions of the window- or pasteprobe,delivered with the Viskomat XL . . . . . . . . . . . . 64
58 Flowcurve of a silicon oil with 12.5 Pa*s measuredwith the fishbone probe of the Viskomat XL . . . . . 65
59 Flowcurve of a silicon oil with 12.5 Pa*s measuredwith the window probe of the Viskomat XL . . . . . . 65
60 Vaneprobefor the Viskomat XL. The basket is aninlet for the vessel to minimize wall slippage. . . . . 67
61 Comparison of the vane probe and the mortar probewith silicon oil as Newtonian fluid. . . . . . . . . . . . 70
62 Comparison of the vane probe and the mortar probewith a Bingham fluid. . . . . . . . . . . . . . . . . . . 70
63 Chiller outlet and filler. . . . . . . . . . . . . . . . . . 71
64 Chiller inlet. . . . . . . . . . . . . . . . . . . . . . . . 72
65 Chiller on/off button (red), on/off button for the cool-ing machine (green) and the controller. . . . . . . . . 72
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