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Topic: Reading a strain gauge signal on Labview via arduino (Read 1 time) previous topic - next topic

straits

I've posted a similar question months ago concerning the reading of a full wheatstone bridge (four strain gauges on a bar) and I've managed to acquire signal on Labview with little trouble.

However, I am now trying to do the same thing, with the same amplifier (ina125P) but for a single strain gauge of 120 ohms in a bridge with 3 resistors of 120 ohms each - and 1% accuracy for their resistance. For some reason I cannot read anything but 0V or the maximum of around 4.6 V - implying something is wrong with the circuit or the gauge.

I managed to acquire signal from a quarter bridge arrangement using a strain gauge card and some older drivers -so it's fine without an arduino. The schematic for the full bridge strain gauge arrangement can be found here http://cerulean.dk/words/wp-content/handsketch.jpg

I am using a near identical arrangement for the quarter bridge, which leads me to believe that the problem could be in which terminals I am connecting to the amplifier; since the strain gauge is functional, and the Labview code only reads the A0 input in any case. There is an attachment of what I am trying to do on the breadboard (it IS a bit small so a part of it could be difficult to see).

Any ideas would be appreciated.

wwbrown

With a better picture and/or schematic and source code it is difficult to help.

wade

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