A NEW APPROACH TO MEASURE LOW TEMPERATURE VISCOSITY OF DRIVE LINE FLUIDS
Low temperature viscosity of automatic transmission fluids, gear oils and hydraulic fluids is an important aspect of equipment operation. This property is currently measured by ASTM D2983, which is commonly referred to as Brookfield viscosity. A new automatic method of measuring the D2983 viscosity at low temperature is presented. Once a measured volume of sample is placed in the sample chamber, the viscometer lowered into position, and the process started, it is entirely automatic. The sample is thermally conditioned per the requirements in Annex 2 of D2983. By using thermoelectric sample conditioning for both the preheat and low temperature segments the test can be completed in the same chamber. At the end of the thermal conditioning, the viscosity is measured at the spindle speeds listed in D2983. By utilizing a digital viscometer with programming capability and temperature sensor, the viscosity measurements are completed automatically at the end of test. The viscosity measurements are done at discrete intervals for a set period of time which are included in the test's data file.