Optical Rotary Torque

An established technology, Optical Rotary Torque sensors use a pair of gratings attached a short distance apart on a strain-sensitive shaft to modulate a light source. As torque is applied to the shaft, a slight twist results which changes the alignment of the gratings and thus varies the light transmitted through to a detector.

A simple and effective concept, the Optical Rotary Torque technology excels in applications requiring:

• Low Torque Ranges - since there is no effective minimum shaft size required for this technology, very low torque levels can be measured with systems starting at 1 ozf.in Full Scale
• High Bandwidth - the light monitoring devices offer exceptional bandwidth with frequencies up to 50kHz possible

While simple in concept, the Optical devices tend to be more costly than competing technologies. For most standard applications, therefore, sensors based on other concepts - such as TorqSense - tend to be preferred.

But when the demand is for low torque and/or high bandwidth, the alternative options quickly drop out leaving Optical's as the only viable solution.