I have a problem using an instrumentation amplifier(INA122),
www.ti.com/.../ina122.pdf
I've used the scheme in page 9 figure 5. Is powered by +5volt from arduino diecimila.
The bridge have 2 resistors of 10k ohm ,one of 100 ohm and the last is a 3wires pt100(due to this kind of sensor i conect one the 3rd wire to the pin2). The circuit is powered by +5volt from arduino. The problem is that the output is 0v on Vout, so amplifier does not amplify my input imbalance when i change temperature on the sensor(im sure its working rigth because its resistance value is the same as its datasheet). I've tryed to change Rg but nothing, the output is always 0v(i used a Rg of 1.2k and 10k). All connections are right and without short circuits.
I have on Vin+ and Vin- 3.8 milliVolt and 3 milliVolt on output, and the output don't change.
What i'm doing wrong?