Torsion Strain measurements: wireless? 2

[brmech]

I want to measure strain realtime on a 6" diameter rotating shaft. I was thinking it would be nice if there was a strain gauge system that could use radio frequency (go bluetooth) to transmit the volatage output data from my full wheatstone bridge to a storage medium. Does any one know of a product out there that can do this?

 

[Ron]

Check with MicroMeasurements in Raleigh, NC or with Analog Devices. I have seen a device advertised, but don't remember where. I have used products from both of these companies and their product lines are pretty extensive so you might find something there.

Have you considered photo-stress measurements?

I have done torque measurements with conventional wire connected strain gauges, but obviously done with compromise since you can only wrap so much wire around the shaft before it unwinds and rips your gauges off!!

 

[brin]

I used a FM/FM telemetry system to measure strain and torque on rotating propeller shafts. The instrument was made by PMC out of Florida. You should still be able to rent it complete with transmitter and receiver. I think Intertechnoloy

http://www.intertechnology.com/Lebow_Rotating_Torque_Sensors.html

sells this product line.

The system worked OK, although we did have problems with dropouts at different shaft positions, and with signal drift. The PMC system works on the FM broadcast band, so it is important to stay away from strong radio stations, etc. This was a bit of a problem on marine vessels.

There are other systems out there, I will post if I find it.