Gap measurement techniques 2

[jackdaniels]

I am trying to measure a 2mm gap (between metal panels)at five positions across its 50mm breadth. The horizontal gap is around 1500mm in length and I need around 500 readings from this length. The accuracy + precision needs to be within 0.010mm. I have attempted to use strain gauge technology, but can only achieve 0.020mm acc + prec due to systematic and random errors. Is it a case of simply tightening up on my 'Wheatstone bridge' method, or is there something - such as a capacitance gauge - out there that would allow me to meet this requirement?

 

[Don039]

Try a company by the name of Capicitec - they have quite a bit of experience in this area.

 

[dgallagher]

Eddy Current probes used for shaft vibration and axial position could also be used in this application and meet your accuracy needs. Feel free to contact directly at dgallagher@reliabilitydirect.com to discuss the application.

 

[jackdaniels]

Thanks, Don039 and dgallagher.
I'll investigate these links you have provided.

Must admit I hadn't thought of Eddy Current, probably due to the small area a probe would have to be placed or travel in. My experience of Eddy Current has always been for an external use, not the void inbetween, so probe size and manipulation was never a problem.
Thanks again, guys.

 

[carlorom]

Hi

Have you considered some photogrammetric techniques? With the right stereophotography setup one should be able to get this sort of accuracy. Contact a local photogrammetrist or failing that speak to some instrument manufacturers like Leica which specialise in this area. - good luck.