High-precision temperature-measuring device

The utility model discloses a high-precision temperature measuring device, which comprises a left half arm and a right half arm. Wherein, the left half arm is composed of a constant resistance R1 and a platinum resistance temperature sensor Rt in series. The right half arm is composed of an isolated follower IC1 and constant resistances R2 and R3. In addition, the left half arm is connected with the right half arm in parallel, which are jointly and electrically connected with a constant power source. The platinum resistance temperature sensor Rt adopts three-wire connecting system. Two lead resistances Rx1 and Rx3 are connected with loops R1 and Rt in series. Another lead resistance Rx2 is connected with an input terminal of a meter amplifier IC2 with high input impedance. Besides, an output terminal of the meter amplifier IC2 is electrically connected with contacts of the constant resistance R2 and R3. The utility model adopts high-stability constant current source to provide electric power for a measuring bridge and isolates electric power for a left and right half bridge, thus fulfilling linear rectification to the platinum resistance and electric bridge and showing higher measuring precision.