Thermocouple Amplifier Circuit Diagram. Thermocouple and pt 100 rtd the rc is to filter out 50hz pick up in thermocouple wires if near heater wiring and also reduces reading jumps when high current three phase. The effects of temperature change on dissimilar metals produces a measurable voltage.
R1 is a offset null use or add if required. The op07 is in a non inverting amplifier so as not load the mv of thermocouple the zeners are to protect circuit if junction contacts heaters or the earth gets broken. The tl072 is a fet input opamp used here as a summing amp.
The rc low pass filter formed by r6 and c2 reduce the mains hum or 50 hz pickup of long thermocouple cables laid close to high current heater wiring.
A thermocouple is a terrific way to measure temperature. But to make that measurement you need an amplifier cir. The op07 is in a non inverting amplifier so as not load the mv of thermocouple the zeners are to protect circuit if junction contacts heaters or the earth gets broken. R1 is a offset null use or add if required.
