A centrifuge ball viscometer was developed for fluids with a wide viscosity range. The viscosity &eegr; could be obtained from an empirically derived relationshipac=b(&eegr;V∞)c, whereacis the applied acceleration,bandcare empirically determined parameters, andV∞is the terminal velocity. The key features of this viscometer are as follows. (1) A wide range of viscosities can be accommodated: about 10−1to 105Pa s with 1010Pa s achievable, in principle, for about a one‐data point per day measurement. (2) A computer controlled motion controller allows rotation speed of the motor varying over a speed of 1 to 5000 (±0.01) RPM (revolutions per minute). Thus, measurements at different low shear rates can be accomplished. (3) About 0.5 ml of sample volume is needed for the present setup. (4) The temperature can be maintained from ambient to over 400 °C (±0.05 °C). (5) The samples are isolated by sealing them in glass tubes, a potential advantage when dealing with polymer solutions, polymer melts, and/or those systems subject to oxidative degradation. ©1994 American Institute of Physics.