ASTM D2162

Why is the ASTM D2162 practice for basic calibration of master viscometers and viscosity oil important?

Because there are surface tension or kinematic viscosity differences, or both, between the primary standard and kinematic viscosity standards, special procedures using master viscometers are required to “step-up” from the kinematic viscosity of the primary standard to the kinematic viscosities of oil standards. Using master viscometers calibrated according to this practice, an operator can calibrate kinematic viscometers in accordance with specifications ASTM D446. Using viscosity oil standards established in this practice, an operator can calibrate kinematic viscometers in accordance with specifications ASTM D446. 

Summary of ASTM D2162 practice

Two or more master viscometers, having calibration constants in the 0.001 mm²/s² to 0.003 mm²/s² range, are calibrated with water at 20 °C. The kinematic viscosities of two or more oil standards are measured at 40 °C in these two master viscometers. Corrections are made for buoyancy and, where necessary, for temperature and surface tension. A third master viscometer, with a calibration constant of 0.003 mm²/s² to 0.009 mm²/s² , is then calibrated at 40 °C with the two standard oils and its calibration factor calculated at standard conditions for water at 20 °C. In like manner additional viscosity oil standards and additional master viscometers are calibrated at 40 °C using the average results from at least two master viscometers or two oil standards. Steps between successive calibration constants or viscosities increase by a factor of three or less until the desired viscosity range is covered. Oils are calibrated at other temperatures using the average result from at least two master viscometers.

Why should you use a Tamson Viscosity bath?

Tamson offer two types of viscosity baths for practice ASTM D2162 using master viscometers. The robust Tamson TV16000 viscosity bath with integrated cooling can be operated from +10°C up to +60°C (41..446°F). The TV7000DC viscosity bath can be operated from ambient +10°C up to +230°C (41..446°F), the widest range in the industry. With the use of the built-in cooling coil and an external Tamson cooling circulator, span lies 5°C above the temperature of the cold flow of the external cooling circulator. The TV16000 and TV7000DC have a cover with nine and seven openings and lids respectively. These openings accommodate master viscometers in viscometer holders. A bath overflow outlet protects from expanding bath oil when the bath filling is expanding at higher temperatures. The viscometer bath has a drain to remove the bath content. The bath is fitted with a double window of which the front pane is detachable for cleaning purposes.

Please contact our sales team (sales@tamson.nl) to get a quotation. Or visit our webshop to get price and technical information for a viscosity bath and accessories to cover the calibration of master viscometers and viscosity oil standards conform to ASTM D2162.