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https://www.senbasensor.com/the-adaptability-of-infrared-thermopile-sensors-to-the-environment.html

Fog, rain and dust rather than night and day will affect the accuracy of temperature measurement of infrared thermopile sensor. The reason is that the infrared light will be attenuated to some extent under these conditions, but its attenuation will not be very large. Generally, the actual temperature measurement accuracy will not be greatly affected. The infrared probe has also been applied in the fire-fighting and fog conditions.

Effect: dust ＞ rain ≈ fog.

The situation of weather change is quite complex. If the temperature is not changed suddenly, but changed slowly in winter and summer, day and night, and inside and outside the house, the resistance of the infrared thermopile sensor measuring the ambient temperature will make compensation, and the subsequent circuit will calculate this compensation and convert it to the actual temperature measurement value. Under this circumstance, the weather change or the environmental temperature change will not affect the temperature measurement of the sensor. The other case is sudden temperature change, that is, fire baking, putting into the refrigerator, facing the fan, throwing into the water, covering with hands, and there being a heat source near the PCB sensor, etc. In this case, the sensor will appear the phenomenon of "heat shock", that is, the temperature measurement will be inaccurate or drift in a short time without reaching the thermal balance, which is possible to all thermoelectric reactor sensors rather than just our products. The main reason is that the sensor is packaged with TO metal tube shell. When the sensor is used in the sudden temperature change environment mentioned above, the TO tube wall will also undergo intense heat exchange, resulting in sudden heat or sudden cooling of the tube wall. Then the TO tube wall will also produce infrared radiation under temperature change, which is received by the sensor, forming thermal noise signal. Next, the signal is superimposed with the infrared radiation of the actual measured object through the filter, and makes the temperature measurement of the sensor inaccurate.

Therefore, in order to avoid the above situation, the TO packaged sensor is usually placed in the specific product shell to increase the heat capacity of the temperature measurement system and improve its resistance to "heat shock" phenomenon, such as ear thermometer and new thermoprobe. Of course, if the applied occasions can avoid the above situation, you can also consider directly using them.

Senba Sensing Technology Co Ltd is one of professional pir sensor manufacturers. We provide Infrared Thermopile Sensor, Digital PIR Sensor, passive infrared sensor and so on. Want to know more? Please contact us.