Recent content by AJone

"Proof may just be lack of Imagination"

The resistor value itself will not get you the output. The relative change in resistance is what is needed. Assuming we are talking about a diffused resistor, the resistor geometery and orientation, crystal orientation, doping concentration/depth, and strain distribution and direction among...

As jsummerfield noted, an absolute pressure transducer most commanly has a sealed referenced chamber that makes for a true PSIA reading. The reference chamber is most often a vacuum on the back side of the measuring diaphragm and should not be affected by ambient conditions within the accuracy...

Flat and Corrugated Diaphragm Diaphragm Design Handbook by Mario Di Giovanni This book includes a couple of chapters on bellows and presents simplified algebriac equations useful for optimizing designs.

I suppose there may be other candidates such as laser welding, but most of the small bellows welding I've seen is done with electron beam welding. Wengate is one manufacturer and systems are very expensve.

Has anyone heard of fittings called "Fas-Test"? My understanding is that they accept NPT threads but seal on the face of the fittings instead of the threads. I'm not looking for any reliability info, just who might have sold/made these items. Thanks, Mark

http://personalpages.tds.net/~leitechmike/igp.htm http://www.auto-met.com/fowler/digi-thread.html Here are some more time consuming methods

Would dropping a cyrogenic pressure sensor in the tank work? We have standard models down to 0-15PSIA that are around $1500.00 . Lower ranges or PSIG units would require additional charges. If you would like additional information, you can call 740-965-9340.

Most stock sensors under $20 have a sensor that is exposed to the media and attached with RTV. The RTV is probably not good for the application. One low cost possiblility may be a small silicon pressure sensor mounted on a flex circuit sold by keller. Not very accurate and you must create a way...

This may not be of any use, but this is about the thickness of your average strain gage which is also made of polymide. Maybe your material is suitable to have a strain sensitive foil printed on it or you could have a custom strain gage made to insert in place of the current membrane. Also...

It's a little out dated, but the book "dimensional Instability" by Marschall from 1977 is a good primer. 2024-T6 is often employed for low capacity sensors. There's couple charts for microyield behavior of of this alloy I could provide if you interested. What kind of alloys have you...

http://www.microgroup.com/

Swagelok is a good safe reference for this. Check out the following link: http://www.swagelok.com/downloads/webcatalogs/MS-01-147.pdf Obviously the max rating will depend on the application, forces on the connection, connection material, safety factors, etc. NPT threads are capable of sealing...

If the bearings are damaged due to deposits instead of wear, you be able to clean them in a solution such as vineager on a regular basis.

I assume you might be trying something like calibrating your test equipment/amplifier. Here the characteristics of the circuit that provides the signal may be important. In this case you may want somehting like a strain gage simultor. BLH sells a couple of models. Cheaper methods such as...