You should design an instrumentation amplifier. 1% tolerance resistor are available in the E6 series (1.0, 1.5, 2.2, 3.3, 4.7, 6.8) over the

range 1 to 6.8M, and use OP-97E op-amps from stable DC supplies of 15V.OP-97E(Vos=60uV, Ios=250pA, Ibias=250pA)

The output is to go to an ADC with an input range of 5V and must NOT clip or saturate with peak loads as then data is lost.

The amplifier is to work with 350 full bridges with a bridge energization voltage of 10V. Grounding arrangements may vary so the common mode

voltage may be 0V, +5V or -5V.

The amplifier must allow measurement of peak strains of up to 5 millistrain with a gauge factor (dR/R)/(dS/S) of 2.1 exploiting as much of the

available ADC input range as possible. The effect of offset errors due to common mode voltage or op-amp effects must be less than 5% of the

peak load signal without trimming or adjustment in any of the grounding configuration.

Last Updated on February 12, 2018

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