ASTM D5133 low temp, low shear rate, viscosity/temp dependence of lubricants
ASTM D5133 standard test method for Low Temperature, Low Shear Rate, Viscosity/Temperature Dependence of Lubricating Oils Using a Temperature-Scanning Technique
6. Apparatus
6.1 Test Cell, shown in Fig. 1, consisting of a matched rotor and a stator of the following critical dimensions:
6.1.1 Rotor dimensions for: critical length is 65.5 mm (+/- 0.1 mm) and critical diameter is 18.40 mm (+/- 0.02 mm).
6.1.2 Stator dimensions for: critical diameter is 22.05 mm (+/- 0.02 mm) at whatever length will satisfy the immersion depth when the upper oil level is a minimum of 15 mm below the cooling liquid level over the entire temperature range.
6.2 Viscometer Drive Modules, rotational viscometer drive modules capable of producing an analog signal to an analog-to-digital converter or other analog signal data processor such as a strip-chart recorder.
6.2.1 With the rotor and stator described in 6.1.1 and 6.1.2, the viscometer drive module shall be capable of measuring to at least 45 000 mPa•s (cP).
6.3 Test Cell Alignment Device, simultaneously maintains a vertical axial alignment and reasonably consistent positioning of the rotor in the stator to give repeatable torque readout from test to test when setting up the apparatus for analysis.
6.3.1 Viscometer Support, supports the viscometer drive module and aligns it vertically.
6.3.2 Stator Collar, clamps the stator and supports it when the stator collar is attached to the viscometer support.
6.4 A means of providing a dry gas atmosphere over the top of the test sample is necessary to prevent condensation and freezing of water on the oil surface.
6.5 Programmable Liquid Cooling Bath, liquid bath capable of running either the calibration or the testing program with temperature control of +/- 0.1°C over the temperature range desired at 1°C/h.
6.5.1 Temperature Controller, is set up to operate according to two programs, the Calibration program and the test program. At any temperature the controller modulates temperature within 0.1°C of the desired value.
6.6 Computer, Analog-to-Digital Converter, and Analysis Program, means of receiving data from the viscometer drive module and converting this data into the desired information.
6.7 Sample Pre-treatment Water or Air Bath, a programmable water or air bath for both precise control of the test oils at 90 +/- 2°C and immersion time after the sample reaches pre-treatment temperature.
6.8 Calibrated Partial-Immersion Mercury Thermometer, an ASTM 34C thermometer, calibrated at 90°C and reading to +/- 0.2°C.
7. Materials
7.1 Calibration Oil, a Newtonian calibration oil of specified dynamic viscosity and viscosity index over a temperature range of -5 to -35°C.
7.2 Gelation Index Reference Oils, GIR-Series, Non-Newtonian Reference Oils, having Gelation Indices of established values as well as related values for the Gelation Index temperatures.
7.3 Finger Cots, latex, used to close the top of the oil-filled stators when they are in the pre-treatment heating bath and subject to water condensation inside the stator.
8. Sampling
8.1 Approximately a 20 mL sample of test oil is necessary for the test.
