EL-700 (100Ω) platinum resistance temperature measurement circuit

This is a temperature measurement circuit using EI: 700 (lOOn) platinum resistance . The temperature measurement range is +20~+120℃, and the corresponding
output is 0-2V. The output voltage can be directly input into the microcontroller for display and control signals (if the microcontroller does not have an A/D converter, it needs to go through
5G14433 before inputting A). .
    The platinum resistor is connected to the measuring bridge. In order to reduce the measurement error caused by too long connecting wires, a three-wire system is adopted. The signal is amplified by Al
, and the amplified signal is filtered out useless clutter through a low-pass filter composed of A2.
    A standard resistor box is used in place of the sensor during adjustment. When ￡=20℃, adjust RP1 to make the output Uo-ov; when -120℃, adjust
RP2. Make U. -2,ov.
    If lkfl platinum resistor is used , 8.2kfl should be changed to 18kfl, and 20kfl should be changed to 68kfl. RP1 is changed to ZkSl potentiometer.