Rotational Speed Sensors

[GaryE30]

Hello,

I'm working on finding some of the newest rotational speed sensor technology to test out for future use. The application is for measuring turbocharger RPM.

Currently we're using eddy current sensors and have used VR sensors before. VR was used by measuring a flatspot on the shaft. Turbos are getting smaller and smaller and this method has become more of a challenge to fit these sensors in the bearing housings. We are looking to abandon eddy current now because of its inability to accurately measure titanium compressor wheels. I'm curious if anyone knows of any more methods that may be updated (aka new technology)?

I have read about all kinds ranging from a lazer reading a dot on a blade to alternating shaded faces on a compressor nut and using a light.

Anyone have any tips/new ideas?

Thanks!

 

[MacGyverS2000]

alternating shaded faces on a compressor nut and using a light

An IR LED is better than just a light, but that would be my suggested attack vector. You'll have to figure out how to deal with dirty environments, but it's easy and dirt cheap to implement.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[mikekapo]

How about Exhaust Air speed with a formula for a rough conversion from air speed to rotational turbine rpm.
Just a thought. HTH

 

[GregLocock]

Given that CD easily manages your bitrate I think an optical system is the obvious choice, but have no real idea of components.

Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.