I need an idea. I am trying to use a cheap pressure transducer MPX10 to measure pressures up to 10 kPa. I set out to use a standard 3 opamp instrument amplifier but came against a problem. The transducer has a span of 35mV for to 0 to 10kPa input but can have an offset of nearly as much I measure 25mV difference between +ve and -ve outputs with zero pressure.
This means that with the gain set to give 0.5 to 4.5 volts to an AD input the offset takes most of this range. I set the lower point by returning the Vref point to a pot to set zero.
How can I null out this offset
I have attached my circuit
This means that with the gain set to give 0.5 to 4.5 volts to an AD input the offset takes most of this range. I set the lower point by returning the Vref point to a pot to set zero.
How can I null out this offset
I have attached my circuit
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