I'm currently trying to build a circuit on a breadboard that, through a temperature sensor, gives off a voltage which I need to amplify. I'm using a Pt100 sensor with 3 wires (red, blue and yellow) connected in a Wheatstone bridge that I in turn connect to an instrumental amplifier and get an output voltage. I have built pretty much the entire circuit; the schematic is this:
The negative voltage input to the amplifier goes in pin 2 and the positive in pin 3. I'm using 100 Ohm resistors for the Bridge and a potentiometer for the Gain Resistance, but that's not the problem. I don't know how to connect the Pt100 wires in order to get my Wheatstone Bridge. I have thus far built the following circuit in my breadboard:
I have wracked my brains over this and although I'm sure the answer is right in front of me I can't for the life of me see it. My head hurts. I wouldn't know if you need any further information. I figure with the 100 Ohm resistances further up on the breadboard I'm getting the lower 2 that show up in the schematic. I'm not sure anymore though. Everything got messed up in my head somewhere along building it.
I greatly appreciate your help. I looked up how the wires work but didn't understand much. I guess the answer I'm looking for is an explanation of why there are 3 wires, how to connect them and breadboard-related, where exactly (row number, letter) to connect them. Or any corrections to the bridge.