ASTM D2162 Test Method for Basic Calibration of Master Viscometers and Viscosity Oil Standards
12. Calibration of Viscosity Oil Standards at Other Temperatures
12.1 Select a master viscometer having an efflux time between 300 and 3000 s with the oil at the temperature of test.
12.2 If it is suspected that the oil sample might contain solid particles, filter the sample through a 200 mesh (75-µm) filter into a clean beaker. When calibrating with Cannon master viscometers adjust the temperature to 20 +/- 3°C. Charge the viscometer as described in 8.4 or 8.5.
12.3 Adjust the temperature of the bath to the new test temperatures within +/-0.01°C of the test temperature. For temperatures below 15°C, the bath temperature should be constant within +/-0.02°C. When working near or below the dew point, use drying tubes to prevent condensation of moisture in the viscometer.
12.4 Determine efflux time of the oil at the new test temperature as directed in 9.3-9.6. Select another master viscometer having an efflux time between 300 and 3000 s and repeat the determination of efflux time.
12.5 Calculate the kinematic viscosity as directed in Section 10, substituting air density, oil density, and surface tension at the new test temperature for the densities and surface tension at 40°C.
