Dynamic Strain Gage Monitoring

[UCengno1]

I am setting up a test where I will be monitoring a group of strain gages mounted at the root of a tooth on a pinion gear (gage type EA-06-015EH-120). The signal runs through a slip ring to the DA equipment. The loading cycle is about 70 hz max and will be concurrently monitoring 5 separate gages on 5 full bridges. We are borrowing a Vishay 2210 as a front end for our LabView to do our initial testing but am looking for a more economical option for follow up tests. Noise is a worry. Any recommendations on an alternative to the Vishay 2210?

 

[GregLocock]

Well, what features does the Vishay unit have that you don't need?

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[UCengno1]

The killer is the 1500USD/channel price tag of the 2210. You compare it to the 200-300USD price for an Analog Devices 5B38 and it requires some justification and/or some other alternative. The 2210 covers all my possible needs but is there something in the middle ground that would work? Concerning the Vishay 2210, we are probably going constant current but do like the flexibility to choose my bridge type.

 

[GregLocock]

So what doesn't the 5B38 have that you need? My mind reading abilities are on the blink. You'll need a chassis/backplane for the 5B38 at the very least.


Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Strong]

I tried this type of gear tooth strain test over 30-years ago. Slip ring noise was a huge problem. If I had to do it again, I would use telemetry where bridge power and amplification is done on shaft and clean signals are transmitted to your DAQ system. Your instrument system is only as good as the weakest link. Try not to buy these instruments until you prove that they will deliver the signals you need. Also 70-Hz is a rather low frequency for F-max; unless shaft rotation speed is rather slow.

Walt

 

[UCengno1]

Just as STRONG described the group than installed our slip ring is telling me that we will be experiencing noise issues with the 5B38. I am assuming the filtering on the 2210 knocks this out wheras the 5B38 does not?

BCK

 

[cincibcats]

Does the 2120 have some sort of filter. I remember it only having internal bridge completion and amplification.

 

[IceStationZebra]

There are literally dozens of choices here. Are you looking for mobile vs. stationary? 12vdc operation? Self-contained? About the cheapest setup per channel is to use strain gage signal conditioners and run that into an analog-to-digital card in a computer/laptop.

One of my former employers used Validyne MC170 signal conditioning chassis, which worked quite nice even hanging on the outside of off-road equipment. They offer lots of signal options for other uses too. We even had custom cards made up for some odd-ball uses - I think our instrument lab did it, but it was pretty easy.

ISZ