PT100 Temperature Sensor 0 ° C is 100Ω, and the resistance of the resistance is 0.3851Ω/° C. Due to the small resistance value and high sensitivity, the resistance value of the lead cannot be ignored. The Third Line < /u> type connection method can eliminate the measurement error caused by the resistance of the lead line. The principle is as follows:
The three wires and lengths of the three wires caused by the PT100 temperature sensor are the same (ie R1 = R2 = R3). The circuit that measures the platinum resistance is generally unbalanced bridge. One (R1) receives the power end of the bridge, and the remaining two (R2, R3) receives the bridge arm where the platinum resistance is located and the adjacent bridge arm, so that the two bridges have introduced the same resistance value Diversion resistance, the bridge is in a balanced state, and the changes in the resistance of the pT100 temperature sensor's lead wire resistance have no effect on the measurement results.