4-Wire Resistance Meas of Strain-gauges

[hendra@ngms]

Has anyone out there done 4-wire resistance measurement of strain-gauges?  If so, I'd like to discuss the EU conversion algorithms you developed.

A couple App Notes are attached describing the use of an Agilent 34980 Switch/Measure unit -- or any 6 1/2 digit DVM capable of 4-wire Res Meas -- to do this.

[aNIta B]

Hi Hendra-

         So are you trying to measure the nominal resistance of a strain gauge?  And as well, when you ask about EU conversion algorithms- are you just needing to convert voltage to EU?  

[hendra@ngms]

I know this is kind of a long shot, since NI makes all kinds of Strain-gauge input signal conditioners.  And there may be nobody in this community who has done strain-gauges any other way. 

The idea is to use a 4-wire resistance measurement technique of a Digital Multimeter, instead of an excitation and voltage measurement.  So what you are measuring is the very small resistance change in the bridge, not a voltage developed across the bridge.  This is explained in the attachments.  They are too short, not enough information to really develop algorithms.

[aNIta B]

Thanks for that clarification!  It sounds like what you are trying to accomplish is essentially what AI Sense does in our strain gauge modules.  So, unfortunately, I don't have any algorithms I can help you with, but hopefully the rest of the community can help you out.  Have a great weekend!