Thank you for asking a question on our blog.

Torque measurement is basically the measure of force being applied in turning a shaft. When a turning force is applied to a shaft the shaft twists by a very small amount. This twisting produces some deformation in the material of the shaft. This twisting is in a direction at 45 degrees to the axis of the shaft. The shaft effectively stretches slightly in that direction.

The shaft also exhibits a compressive force in the opposite 45 degree direction.

So if you mounted strain gauges at both +/- 45 degrees perpendicular to the shaft axis you should see both the compression and the extension forces.

With regards as to how to measure this whilst the shaft is moving is a more difficult question, it depends on the shaft itself and what you’re doing.

Generally we would use some wireless strain gauges for this application, but that might not be practical for your application.

I’m PhD student and I need to measure the torque transmitted to right and lift wheel by using strain gauges on each shaft connecting between differential and each wheel. without using torque transducers.

Do you can explain the correct direction for bonding the gauge and How I can measure the reading while it rotating.

thank you.

Thanks for asking a question on our blog.

I would suggest contacting a transducer supplier normally, they may be able to advise further. But a good place to start would be a Sensor Article that I recently read that does in fact show a complete circuit diagram.