Reducing excitation voltage for bridge measurements
Reducing excitation voltage for bridge measurements
(OP)
Hello,
I'm using a National Instruments Compact DAQ System for measuring strain gauges. The system allows an excitation voltage of 2V (minimum) for my half-bridge.
Unfortunately the strain gauges I have to use aren't able to stand this voltage and allow only 1V (maximum) excitation voltage.
Is it possible to reduce the excitation voltage between strain gauge and DAQ-System by an stable potential divider e.g. an resistance with 0,01% accuracy in both sides of the half bridge?
Any tip will be helpful...
Karsten
I'm using a National Instruments Compact DAQ System for measuring strain gauges. The system allows an excitation voltage of 2V (minimum) for my half-bridge.
Unfortunately the strain gauges I have to use aren't able to stand this voltage and allow only 1V (maximum) excitation voltage.
Is it possible to reduce the excitation voltage between strain gauge and DAQ-System by an stable potential divider e.g. an resistance with 0,01% accuracy in both sides of the half bridge?
Any tip will be helpful...
Karsten





RE: Reducing excitation voltage for bridge measurements
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"It's the questions that drive us"
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RE: Reducing excitation voltage for bridge measurements
For this I want to reduce the voltage between 9237 and strain gauge...
RE: Reducing excitation voltage for bridge measurements
I presume NI measures the V and mV as part of it's calculation.
Roy
RE: Reducing excitation voltage for bridge measurements
This will be the lowest value for all cases.
What I'm thinking about is putting two extra resistors in the circuit of the half bridge. One after excitation (+) and before strain gauge 1 and one after strain gauge 2 and excitation (-). The measured value will then be wrong - but linear wrong.
To correct the value I could calculate a correction factor and apply the factor in the software after the data acqusistion. There is a formula for correcting the errors coming from cable-resistance.
If I interpret the two extra resistors as cables I will get the right values... hopefully