ASTM D2532 Test Method for Viscosity and Viscosity Change After Standing at Low Temperature of Aircraft Turbine Lubricants
5. Apparatus
5.1 Viscometers, drying tubes, low-temperature bath, thermometer, timer, secondary viscosity standard, filter, and cleaning supplies are described in detail in Test Method D445.
5.2 Viscometer - The viscometer shall meet the requirements of Test Method D445 and be of the type in which the sample can be rerun without cleaning the viscometer. Suitable holders should be used. For convenience it is recommended that the viscometer size be chosen to keep the efflux time between 200 and 1000 s.
5.3 Drying Tubes - Fit the viscometer openings with drying tubes filled with indicating silica gel, using cotton at top and bottom to hold the loosely packed desiccant in place. Provide a cross-connection on the viscometer side of the drying tubes (which can be closed by a pinch clamp or stopcock while liquid is being drawn into the efflux bulb) so that the restriction to air flow will not cause error. Replace the silica gel when a lavender color is noticeable.
5.4 Viscosity Temperature Bath - The constant-temperature bath must be capable of holding several viscometers at once. It must have adequate stirring of the liquid medium (Note 2) and balance between heat losses such that the bath temperature can be maintained at the required temperature +/-0.03°C (+/-0.05°F).
NOTE 2 - Isopropanol or other clear, low-freezing liquid may be used as a bath liquid.
5.5 Low-Temperature Storage Cabinet - If it is desired to exercise the option described in Note 4 (7.4), a low-temperature storage cabinet or bath shall be provided which is capable of holding the required temperature with a variation not to exceed +/-0.3°C (+/-0.5°F).
5.6 Bath Thermometer - Calibrated ASTM Kinematic Viscosity Test Thermometer such as 73F or 74F conforming to the requirements as prescribed in Specification E 1. Other calibrated thermometric devices are permissible provided their accuracy, precision, and sensitivity are equal to or better than the above thermometers.
5.7 Secondary Viscosity Standards.
