Strain gauge based pressure system

[redneckdan]

Anyone ever built a strain gauge based pressure measurement system for measuring chamber pressure? I know there is the pressure trace system but that is kind of pricey. I have taken several instrumentation classes and worked with strain gauges and the national instruments LabView software.

[scrapcan]

Dan,

we built a couple in the mechanics of materials lab. I will have to look to see what equipment we used to record the strain. I remember it being something the instructor found on ebay for cheap. The strain sensors were found the same way. The critical thing with the setups we worked with was making sure the strain sensor was attached to the material correctly.

All the actual measurements were electrical and then converted through calculatiosn to material parameters.

I will look to see if I have my notes handy, if not someone else will be along soon.

[scrapcan]

Dan I just remembered there was an article on building your own strain guage, I think it was in an old issue of handloader magazine. Try doing a search on home made chamber pressure guage. Maybe someone else will have a reference handy, if not I have it at home.

[redneckdan]

Thank you for the info. I do have a lot of experience with sample preparation. I helped one of the grad students with a study involving instrumentation. I had to apply a couple hundred strain gauges to samples. You get good at it after a while.

The Lab View software is very good for a variety of different applications but the software and DAQ cost several grand. I would be looking for alternatives.

Unfortunately a wheat stone bridge for amplification won't work for this. All signal processing would have to be done digitally.


I did some google searching and was not able to locate any strain gauge stuff in Handloader magazine.

[felix]

Military surplus. ... felix

[scrapcan]

Dan I will look in my folder at home and see if I can scan the article for you.

[Ed K]

http://www.mindspring.com/~sfaber1/

[scrapcan]

Dan I sent you a pm, the article is in Handloader 141 witten by Walt Netzel.

[redneckdan]

got it. thank you for your help.

[scrapcan]

No problem at all, just took me a couple days to get it doen for you. Let us know if you make one.

[redneckdan]

I am seriously considering it. Spent a couple hours on digikey sourcing parts last night.

[scrapcan]

That would be great, It did not look to bad to me. Get yourself a bread board and the parts and have at. One other thing you might look at is to see if you have a Ham radio club ( was that you that posted abou that some time back?) in your area and see if one of those guys can help or the electrical engineering students at the college.

[redneckdan]

Ya there is a ham club up here. I also have a former work associate at the university that has a heavy back ground in circuit theory. He used to enlighten me on antenna design theory during our lunch breaks. I used to be his 'lead soldiering technician' for building electronic consoles for the class rooms. 500 connections in a day was normal. As long as there is a circuit diagram I can usually handle building it.

[nanuk]

I had to apply a couple hundred strain gauges to samples. You get good at it after a while.


just make sure your philberg flange meshes well with the grapplegrumit....

[redneckdan]

somethin like that....[smilie=1:

[Knight Templar]

Is this what your looking for?
http://www.shootingsoftware.com/ftp/Instrumenting%20your%20rifle.pdf