With the recent outbreak of influenza A, all kinds of thermometers have once again become an essential item for home health monitoring. The core component of the electronic thermometer commonly used at present is the temperature sensor. The working principle of the thermal sensor is to use the radiant heat effect to cause the temperature of the detection device to rise after receiving radiant energy, thereby changing the performance of the column and temperature in the sensor. By detecting a change in one of these properties, radiation can be detected. In most cases, when the device receives radiation, it causes a non-electrical physical change, and then changes it into electric quantity through appropriate changes for measurement.