High-temperature viscometer for use at 100 kPa. [For naturally occurring silicate melts]

The design of a high-temperature rotational cup viscometer for measuring the viscosity of naturally occuring silicate melts for use at 100 kPa. We include design criteria, a description of the apparatus, and the results of calibration against both a standard oil and a National Bureau of Standards glass to 1322/sup 0/K.