Bi directional milli Volt shunt sensor(rating: 300A/50mV) is fed to the input of AD620 i.e. pin No. 2 & 3 to convert +/-50mV to +/-2V.
Reference pin 5 is set at Ground of +/-12 Ground. +Vs and -Vs is generated through separate DC-DC Converter from +28V DC Input Supply i.e +/-12V.
In case of -50 Milli Volt after setting gain = 40, Output Voltage at Pin no. 6 with respect to Ground is -3.13Volt.
In case of +50 Milli Volt after setting Gain=40, output Voltage at Pin no.-6 with respect to ground is +1.09Volt. But it should come around = 2Volt.
In case of 0Volt input( --0.018 mV), Gain=40, Ouput Voltage = -125mV.
In case of Input= 0V (-0.001 mV), Output Voltage= -63mVolt, Gain = 1