High strains measures

[Domenico]

Hi!

I'd like to measure rubber strain with strain gauges. The strain can reach 15% of original lenght: 150,000 microstrains!

The NI 9237 has a nominal full-scale range of ± 25 mV/V, but with 15% of strain the voltage of the bridge could reach about 65mV/V.

I'm not a strain gauges expert, but i suppose that the bridge configuration is not suitable for this situations.

How can I measure this strains? I'm thinking to supply the gauge with a constant current and measure the voltage with a differential amplifier in 4-wire configuration.

Could it work? Are there some NI modules suitable for this kind of operations?

Thank you very much.

Domenico

Italy

[MarcoL]

Hi Domenico,

I suggest to take a look to the following links that can help you to choose the correct modules and the appropriate conditioning for your strain acquisition:

Measuring Strain with Strain Gauges

Strain Gauge Configuration Types

Strain Measurement with a Strain Gauge

Fundamentals of Strain Gauges

Making Accurate Strain Measurements

Required Signal Conditioning for Strain Gages

I hope it helps! Best regards,

Marco