Optical Displacement Measurement Via Shadow Moire

Can you please specify the density of the grid and the size of the film you need. May be I can supply you the required film. I have some gratings with me, which I collected during my masters degree project in moire'

Did you try these guys ?

Bill Foran and Patrick Hassell of AkroMetrix LLC for

their technical direction with respect to this new technology.

Contact: (404) 486-0880, fax: (404) 486-0890, e-mail: AkroMetrix@warpfinder.com.

goodpedia:

Thank you for the link. More information is always appreciated.

gsuhas:

I am not exactly sure what grating we will need yet. I suspect it to be on the order of several hundred lines/inch (maybe 200-400?). The displacements we are trying to measure are 1-15mm plate deflections. I have heard of gratings as fine as 1000lines/mm, but it is likely that is more than I have use for.

dadw5boys:

I did come accross that web site in my searches, but dismissed it when I looked at their product page. I will take your suggestion and contact them concerning this.

Thanks for the help, guys.

Thanks.

You didn't say anything about the size of the grating you need. On getting this information, I will look in my stock and let you know if I can send something to you

gsuhas:

Thanks for your help. I've never used a Moire method before, so I'm not entirely confident in my predictions, but I will tell you what I am thinking. The gratings I have seen were about 2x2in glass plates about 3mm thick. Since I am measuring a specimens between 75x75mm to 100x100mm I assume that the 2x2in plates would be appropriate.

Also, I see that you used this method in your Master's research which is what I am doing now. Are there any references you would recommend?

Hello

When I did my masters, there was no internet. But, now you can get many more references on internet. Still I will recommend the references on Monday. On Monday only I will let you know about the available films with me.

In the meanwhile, a book on the subject by "Theocaris" is the best reference. (P. S. Theocaris, Moiré Fringes in Strain Analysis (Pergamon, New York, 1969).

Best wishes

Thanks for looking through your collection and for making the recommendations as to literature. I look forward to hearing back from you -- I'm getting excited to make these measurements.

Check with the L.S.Starrett company. They make the "Webber" optical flats.