Measuring Contact Pressure Between Two Plates Using Pressure Sensitive Film

[Kvm90]

Hey, I am working in a lab and I simply can't figure out a method to measure the pressure between two plates I'm compressing.

Here's my set up: I have a metal plate with perpendicular screws attached to another metal plate (I will be putting my sample between these plates). All I do is tighten the washers on the screws to bring the plates together. I want to know the pressure in between these plates as a result of the compression

Any suggestions on how I can do this? I have been trying to figure out a way using strain gauges (because we have them available in the lab) but to no avail so far. If you know of a measurement tool that needs to be purchased feel free to let me know, the lab is funded.

 

[Q_Goest]

The way this is typically done is to use http://www.google.com/search?hl=en&source=hp&q=pressure+sensitive+film&aq=f&aqi=g1g-m2g-v7&aql=&oq=". The film is basically a paper thin sheet of material that changes color depending on the contact stress (contact pressure). The film is generally white and changes color as contact stress increases. The higher the contact stress, the brighter the color. The one I've used is a red/pink color like this:
http://www.pressuresensitivefilm.net/

The manufacturer will send a 'guage' of sorts (a piece of colored paper) to compare the colors to but they can also take your film and run it through a machine that can map the magnitude of the contact stress to a high degree of accuracy. I'd recommend you go this route if you want it done with any accuracy.

Note you can also perform an FEA analysis on your set up to get this contact stress.