Temperature signal acquisition and amplification: the temperature signal acquisition USES PT100 thermistor as the temperature sensor, through the establishment of wheatstone bridge, the voltage signal on PT100 is differential amplification, and then through the AD conversion module sent to the MCU for processing. Lm741 and op07 are built by integrated amplifier chip, which is used for differential amplifier circuit. ADC0809 chip is used for AD conversion circuit. We decided to set the temperature range between 0 and 75 degrees. Its specific connection mode is shown in figure 4.1.