Question: what is the difference between 2-wire 3-wire and 4-wire sensors?
Answer: 2-wire RTD's are mostly used with short lead wires or where close accuracy is not required. third wire provides a method for removing the average lead wire resistance from the sensor measurement. ... The 4-wire circuit is a true 4-wire bridge, which works by using wires 1 & 4 to power the circuit and wires 2 & 3 to read.