Contactless Torque/Power Measurement on Power Station Gas Turbine

Is this project for school, or work?

You might be able to measure the shaft deflection over the 2 meters. Maybe rotary encoders? Maybe optically, if you can scrib a fine line on the shaft.

What do you think? Do you have any thoughts on the subject, or just a burning desire to learn?

Assuming that the machine does not run constantly, you can bond a stress-sensitive polymer film to the shaft, then illuminate the rotating shaft with polarized light from a strobe light and view the stress-sensitive film with a polariscope. This article may give you more and better ideas.

http://www.vishaypg.com/docs/11212/11212_tn.pdf

Just be sure to stand well clear of this thing when it is running. A shaft that large creates air currents that can suck your clothes, your hair, etc. right into it.

GA to post 2.

RJP, please state the needed accuracy and resolution.

RHABE

Need to be able to measure a few fractions of a degree, maybe even down to minutes of arc.

thanks,

We have already done such kind of project for mechatronic systems. Until now we worked on small torque values, but the principle is a contact-less magnetic sensor that has the advantage to measure the torque even at rest (no rotation) around a rotating shaft.

If interested by a project, you can contact Christophe Benoit in the "contacts" page of the site.

The torque induced into the shaft will twist the shaft. The amount of twist is proportional to the torque. 25 years ago the twist measurement would have been made with strain gauge and a slip ring. Today it is done magnetically or optically. You can, for example, wrap encoder tape around the shaft at both ends and bounce a low power laser beam off the tape. The reflected beam will be detected with photo diodes. The phase difference between photo-diode pulses is directly proportional to torque. It's fast inexpensive, and non-contacting.

Check this out http://www.atitelemetry.com/viewproduct-48939.htm, these people may have exactly what you need.

GA