Hi,
I want to use an INA128 to amplify signals from a pressure sensor in the signal range +/-50mV to an output of +-10V. I have built a circuit according to the design in the data sheet using +/-15V supply and a potentiometre to fine tune the gain to 200. The problem is this, the gain varies a lot depending on what signal i put to the amplifier, approximately between 178 and 205 or so. I have tried to use different supply sourses ans different singal sourses. What can be causing this?
Hope you can help!