This is a method of torque measurement in which the brake (eddy current brake, hysteresis brake or vector drive) is mounted in bearings so that it’s housing can rotate freely around the shaft. It is prevented from rotating, however, by a strain gage load cell. This load cell is actually an electronic scale which allows measurement of the reaction torque of the brake

This is a method of torque measurement in which the in-line torque transducer is coupled in the shafting between the motor under test and the brake. The torque in the motor shaft is measured directly, making this method extremely fast and accurate over a very broad range. Torque accuracies better than 0.1% of full scale can be achieved. Since it is measuring the torque right at the shaft of the motor under test, other sources of error (such as bearing drag and windage losses) can be eliminated.

High speed calculations carried in the vector drive accurately estimates the torque at the shaft of the motor.  Accuracies of better than 1% can be achieved. This method allows cost reductions by eliminating the need for either an in-line torque transducer or trunnion mounting the brake.