Infrared thermopile sensors cannot work normally under a rapidly changing ambient temperature (if you suddenly approach a high-temperature heat source (fire) from a low-temperature heat source (ice), a sudden heat source (sudden heat) will be added to the sensor, which will cause sensor heat shock in a short time, you should adapt to the temperature environment for a few minutes before powering on the test, otherwise the circuit may become unresponsive or malfunction. After holding the circuit board or touching the sensor, the process of adapting to ambient temperature also needs to be repeated. The adaptation period depends on the temperature rise of the circuit board (actually the sensor shell). This situation is similar to the ear thermometer. The solution of the ear thermometer is to add a metal thermal resistance to the infrared thermopile sensor to buffer the heat shock. The phenomenon has an inaccurate effect on temperature measurement; another method is that the instruction arithmetic circuit on the software ignores the first 50-100 data (about 10s-30s). The sensor will recover from the heat shock state in a short time. Then use the built-in NTC thermistor of the sensor for compensation to achieve accurate temperature measurement.
There is also a higher cost solution. That is, a heating block or heating tube is provided on the sensor chip or the instrument in advance to keep the sensor environment temperature at a constant temperature, which can eliminate the influence of the environment temperature on the sensor.