BEHAVIOR OF PURE TORQUE AND TORQUE WITH CROSS FORCE MEASUREMENT OF TORQUE TRANSDUCER

摘要

This paper presents the study of behavior of torque four transducers under pure torque and torque with cross force. This explains how cross force causes the measurement result deviating from pure torque. Output signals at every 45° loading angle around measurement axis of pure torque and torque with cross forces at minimum arm length and middle arm length were compared. The result shows that cross force causes sinusoidal-like relationship between the output signals and loading angles. Moreover, cross force effect shifts the sinusoidal graph from x-axis or average of output signals was shifted from pure torque. Sine wave amplitude and degree of deviation from pure torque are directly proportional to cross force magnitude. The same transducers were tested with new developed method, called multi-cross force load procedure. The result from this method agrees with result from torque with cross force measurement. This paper also proposes the concept of evaluating torque with cross force of transducer, which had been calibrated by pure torque. The concept is to compensate the cross force effect using result from multi-cross force load procedure and to include the effect in measurement uncertainty. Furthermore, this research shows the behavior of repeatability and hysteresis error of transducers under pure torque and torque with cross force measurement.