User Manual. Low Shear Viscometer LS 300. prorheo GmbH Bahnhofstr. 40/ Althengstett Tel

Transcription

1 User Manual Low Shear Viscometer LS 300 prorheo GmbH Bahnhofstr. 40/ Althengstett Tel

2 1. Introduction Measuring system Principle of Operation Setting up the instrument Description of measuring head Procedure Starting operation Leveling Starting Software LS Zero point adjustment Measurements Filling the measuring system Measurement Analysis Define Measuring Specifications Start with Choose Measuring System Definition of Flowcurve Options Examples of Measurement Definitions and Data LS 300 Blockschema Representative values and part list Safety Instructions Technical Data LS

3 1. Introduction 1.1. Measuring system The Low Shear 300 is a rotational rheometer based on the Couette principle (measurement bob in a rotating cup). It is particularly suited for rheological measurements on biological substances (biorheology, hemorheology) and fluids of very low viscosity, f. e. fluids based on water or alcohol. The highly sensitive torque measuring system ensures rapid response to changes in the torque value. It is, therefore, possible to observe the elastic behavior of such substances by the determination of relaxation curves. The software LS 300 controls the LS 300 and assures an optimal adaption of the measuring program to the test substance.( so an optimum combination of the measuring program to test substances can be obtained.) The results are stored and can be printed as flow curves Principle of Operation The temperature-regulated, interchangeable measuring cup is driven by a speedcontrolled motor incorporated in the measuring head. The speed is controlled by software and continuously variable programmed in the range ~10 2 to ~10-2 rpm. The measuring cup of the coaxial measuring system, rotating at accurately defined speeds, exerts a torque on the measuring bob through the test substance. The interchangeable measuring bob is attached to a tilting system on which is fixed a multi-pole magnet arrangement and mirror. The complete tilting system is suspended on a torsion wire. An arrangement of electromagnetic coils, concentric to the pivoted magnet system, is rigidly mounted within the measuring head. Using a photo-electric system, the angular position of the bob is monitored by the mirror. When the pivoting system undergoes a deflection caused by a torque exerted on the bob, a regulating current is produced by the photo-electric system in conjunction with the compensation amplifier. This regulating current passes through the electromagnetic coils, and produces an electromagnetic torque on the multipole magnet which is in equilibrium with the mechanical moment. This regulating current is proportional to the torque prevailing on the bob and thus also to the torque prevailing at the bob and thus also to the shear stress. 3

4 2. Setting up the instrument Avoid vibrating the measuring head (1) (floor, building). Also avoid air currents. Place the measuring head on weighting table and the control unit, PC etc. on a separate table. Measuring head 4

5 2.1. Description of measuring head (4) (5) (3) Front (7) Rear (8) (6) (3) Sight hole (keep closed) (4) Zero point setting (5) Lever for lowering measuring bob (6) Connection to power supply (7) Water connection for circulation thermostat (8) Connection to PC 5

6 2.2. Procedure - Connect circulation thermostat to water connections - Fill measuring cup with water and check temperature with a thermometer. Then adjust. - Insert measuring cables into control unit - Connect control unit and PC - Connect mains 6

7 3. Starting operation It is recommended to start with measuring system 1. Raise lever to upper position. 2. Insert the empty, thoroughly cleaned measuring cup. Even the smallest particles can give rise to disturbances. 3. Insert the thoroughly cleaned measuring bob. 4. Slowly lower lever as far as limit stop. The measuring bob descends into the measuring cup. 7

8 3.1. Leveling The black feet on the left and right of the measuring head are rotated to adjust the vertical position of the measuring axis and suspension wire. The measuring bob must hang concentrically in the measuring cup. The measuring bob suspended in the cup can be regarded as a spirit level. Left side of measuring head is too low. Rotate the left foot to the left. 8

9 Correct: 9

10 3.2. Starting Software LS 300 When the software is started, you will see the following window: On the left hand side you see several functions: - Zero Point adjustment - Measurement - Analysis - Define Measuring Specification - Options 10

11 3.3. Zero point adjustment When substances are measured zero point setting must be done with the measuring system empty. After pouring the substance the zero point must remain unchanged. The software checks, if the LS 300 measuring head is correctly connected to the control unit. If not: Please make sure, that the control unit is switched on and all cables are connected. If everything is ok, check the connecting parameters in Options. 11

12 Always start on the highest Range (normally 5). - Turn knob (LS 300 measuring head) until display shows reading less than +0,03. - Set Range 4 - Turn knob, if necessary, until reading is less than +0,03. - Repeat this for Range 3, 2 and 1. When finished, press ok-button. Please wait and do not touch the LS 300 measuring head or the measuring system. The zero point will be adjusted by software. When adjusting is finished, please confirm. 12

13 4. Measurements 4.1. Filling the measuring system Allow time for bob to center, help a bit by hand if necessary. Look out for air bubbles! Prick air bubbles open with a needle and squeeze them out Measurement Choose a Measuring Definition in the list on the right side. If you want to measure in a special range, you can select this range. 13

14 Input sample number (optional) and click Start Measurement. While measuring is done, you see the data in this window. 14

15 When measurement is finished you can store the data. 15

16 5. Analysis For analysing stored data, select Analysis : click to open File You see the measured data. You may give a comment or select Data or Chart. In the Data-Window you can export the data to an Excel-file. Here you can calculate viscosity by using the standard rheological models: Newton, Bingham, Steiger-Ory, Casson. If there are any further calculations you need, please contact us. 16

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18 6. Define Measuring Specifications There are possibilities to define a measuring: - Measuring of flow curve - Frequency sweep - Amplitude sweep - Temperature sweep 18

19 6.1. Start with Choose Measuring System Measuring systems MS-LS 1-6 X4 CrNiMoN18.14 R i = 3mm R a = 6 mm α = 15 MS-LS 2T-3T TiAl6V4 R i = 3 mm R a = 6 mm L = 21,5 mm α = 20 MS-LS 3-4/3-5* X4 CrNiMoN R i = 1,75 mm / 1,875 mm* R a = 2 mm L = 3,5 mm α = 20 MS-LS 1-1/1-7* X4 CrNiMoN18.14 R i = 5,5 mm/5,75 mm* R a = 6 mm L = 8 mm α = 20 MS-LS 2T-2T/2T-8T* TiAl6V4 R i = 5,5 mm/5,75 mm* R a = 6 mm L = 20 mm α = 20 For MS-LS 2T and MS-LS 3T protecting lids are available. (T = Titanium) 19

20 6.2. Definition of Flowcurve Defining of flowcurve: Diagram window Note: Always choose measuring system first. Version: User manual LS 300 [ E-Ley Elektronik] 20

21 7. Options Selection of - Language - ComPort connection to control unit - Enable password (defining of measurement methods and zero settings) - Measuring time (One point measurements) - Julabo connection 21

22 Definition of measuring systems: 22

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24 8. Examples of Measurement Definitions and Data 24

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28 9. LS 300 Blockschema 28

29 10. Representative values and part list Representative values (LS 30rotation modus) step Modus) Step n [1/min] 1 0, , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

30 Measuring system (rotation modus) Measuring ranges depending on used system: Cup Bob Volume min Viscosity max Viscosity ml mpas mpas 1 1 0,5 4,1E-03 1,9E+05 2T 2T 0,6 1,8E-03 8,3E+04 2T 3T 1,5 3,4E-02 1,1E ,07 1,3E-01 6,0E ,07 6,3E-02 2,9E ,5 2,1E-03 9,5E ,5 2,1E-03 9,5E+04 2T 7T 0,6 9,1E-04 4,3E+04 2T 8T 0,9 9,3E-04 4,3E+04 Parts List Measuring system 1.1 DIN Measuring system 2T.2T DIN (Titan) Measuring system 2T.3T DIN (Titan) Measuring system 3.4 DIN Measuring system 3.5 DIN Measuring system 1.7 DIN Measuring system 2T.8T DIN (Titan) Measuring bob 1 DIN Measuring bob 2T DIN (Titan) Measuring bob 3T DIN (Titan) Measuring bob 4 DIN Measuring bob 5 DIN Measuring bob 6 DIN Measuring bob 7 DIN Measuring bob 7T DIN (Titan) Measuring bob 8T DIN (Titan) Measuring cup 1 DIN Measuring cup 2T DIN (Titan) Measuring cup 3 DIN 30

31 Measuring head complete Parts List Pos. 1 Measuring head complete Pos. 2 Foot, adjustable Pos. 3 Foot support pad Pos. 4 Torsion wire Pos. 5 Lever Pos.6 Water connection screw (2 pieces) Water hose (max. temperature 100 C)

32 Measuring bob support, complete Parts List Measuring bob support, complete Pos. 1 Support axis Pos. 2 Mirror Pos. 3 Rubber retainer Pos. 4 Bearing ball

33 Measuring tower complete Parts List Measuring tower, complete Pos. 1 Tower with fixing screw (6) Pos. 2 Cover Pos. 3 Fixing screw Pos. 4 Adjustment knob Pos. 5 Rotation mechanics

34 12 Safety Instructions Compliance with these safety instructions does not relieve him/her of his/her obligation and duty of selfresponsibility to ensure safety, health and environmental conservation, to rule out any possible hazards or stresses for himself/herself or other third parties and to limit these to an acceptable level of residual risk. It is prohibited to operate the LS-300 in moist and wet areas and those areas with a corrosive chemical atmosphere. It is prohibited to operate it outdoors. Protect the device, and particularly its electrical equipment from moisture penetration and ingress. Caution: Dangerous Voltage! Dangerous voltages (230 V AC) are used in the LS-300. The mains power supply line carries dangerous voltage. The LS-300 should be connected only to a mains power supply with 230 V AC and a grid frequency of 50 Hz. Liquids and aerosols should not penetrate into the electrical equipment. In case of hazardous situations, turn off the mains switch immediately. The LS-300 is de-energized electrically and becomes voltage-free when the mains switch is turned off. The mains power supply lines and the signal cables may represent a hazardous risk of stumbling if they are not laid or installed properly. Lay the cable so that it is protected and outside the road traffic zone. Servicing activities on the electrical equipment and the mechanical components of the LS-300 such as maintenance, inspection and repair work should be carried out only by competent persons. The surfaces of the device should never be cleaned with liquids that are unsuitable and solvents (inflammable, explosive or chemical solvents such as alcohols or nitro thinners). Dirt and contamination on the surfaces should be removed only with a dry or slightly damp cloth, which has been moistened with a suitable industrial or common household all-purpose cleaner. Operate the device only at installation sites protected against mechanical hazards. 34

35 In particular, the LS-300 should not be turned over or hit by a vehicle. While transporting the device, ensure that suitable packaging is provided and that the load is properly secured. Professional servicing must be initiated for the LS-300 after it has undergone considerable mechanical damage. Prevent the LS-300 from being handled and operated by unauthorized persons. The LS-300 must be checked regularly, but at least after four years, to ensure compliance with the safety regulations BGV A 3. In particular, continuity tests must be conducted on the protective earth conductor system. The LS-300 should not be operated in explosion-prone zones or in corrosive or abrasive chemical atmospheres. The user should not open the electrical equipment or remove the protective housings and covers. The LS-300 should be operated only in dry rooms at normal room temperature and atmospheric humidity. Devices that are very cold must be kept for at least 6 hours in normal room temperature before being connected to the mains power supply. Non-compliance with this instruction may cause damage to the electrical equipment within the device as a result of condensed water formation or it may cause a substantial hazard for the operator on account of electric current. The mains power supply lines and the signal cables should not be subject to mechanical stresses such as stretching, pressure or shearing off. It is basically prohibited to tamper with safety devices such as, for example, the micro fuses. In case of failure of the safety devices or mechanisms, the device should not be operated until it has been properly repaired. The LS-300 should not be operated if serious safety-related defects have occurred. After the occurrence of major defects, the device must be de-energized and prevented effectively from being switched on again until proper and professional servicing and repair work has been carried out. In the event of fire, the device must be extinguished with suitable extinguishing agents. Suitable extinguishing agents are: ABC powder, CO 2 or AB foam When using the fire extinguishers, ensure a safe distance of at least 1 m from the electrical equipment. Follow the relevant fire-fighting provisions and the fire safety regulations of your organization. 35

36 11. Technical Data LS 300 Mains supply: Alternating current 50 or 60 Hz; 110 to 240 V. Power input less than 50 W. Rotational speed: 0,001 to 150 min -1 Speed tolerance: Viscosity range: 0,5% of nominal value 1.5 * 10-3 to 10 7 mpas Depending on measuring system Shear rate range: 2.8 * 10-4 to 370 s -1 Depending on measuring system Shear stress range: 20 * 10-6 to 0.2 Pa office@prorheo.de 36