ASTM D2983 for low-temperature viscosity of lubricants by Brookfield viscometer
ASTM D2983 standard test method for low-temperature viscosity of lubricants measured by Brookfield Viscometer
4. Summary of Test Method
4.1 A lubricant fluid sample is preheated, allowed to stabilize at room temperature, and then poured into a glass cell with a special spindle. The glass cell is then placed into a pre-cooled cold cabinet set at a predetermined test temperature between +5 to -40°C for 16 h. Then a viscometer is utilized that rotates the specified spindle within the sample at the speed giving a maximum torque reading on the viscometer. The resulting torque reading is used to calculate the viscosity of the oil.
5. Significance and Use
5.1 The low-temperature, low-shear-rate viscosity of gear oils, automatic transmission fluids, torque and tractor fluids, and industrial and automotive hydraulic oils, Annex A4, are of considerable importance to the proper operation of many mechanical devices. Measurement of the viscometric properties of these oils and fluids are often used to specify their acceptability. This test method is used in a number of specifications.
5.2 This test method describes how to measure apparent viscosity directly without the errors associated with either interpolation or extrapolation of experimental data.
NOTE 1 - Viscosity values obtained by either interpolation or extrapolation are subject to errors caused by gelation or non-Newtonian response to rotor speed, or both. Only in the case of known Newtonian oils is interpolation acceptable for the purpose of calibrating the rotor and glass cell. If such viscosity versus temperature plots are required, they can be made by the procedure outlined in Annex A1.
