This may be redundant for many experts who have been studying temperature measurement for many years, but it is still necessary to emphasize the concept and principle of contact temperature measurement, because a large number of facts show how easy it is for people to ignore contact temperature measurement in practical applications. Wen’s important details.
The principle of contact temperature measurement is that the temperature sensing part of the temperature sensor is in contact with the measured target (temperature field or object), and when the temperature of the temperature sensing part of the sensor reaches the temperature of the measured target through heat conduction or heat exchange, The temperature measured by the sensor is the temperature of the target being measured.
But please note that in practice, the sensor not only conducts heat exchange with the measured target, it also conducts heat exchange with the environmental medium in which it is located. Therefore, the temperature measurement part of the sensor often reaches a heat exchange equilibrium state with the measured target in advance before reaching the temperature of the measured target (that is, the absorbed heat in the front and the dissipated heat in the back are balanced on the protective tube, and only The temperature of the measured target can only be reached when the heat absorbed by the front is much greater than the heat emitted by the rear), resulting in a dynamic deviation between the own temperature and the measured target. This is a common source of error in contact temperature measurement. Commonly used in surface temperature measurement, small space temperature measurement and insertion temperature measurement with too shallow insertion depth.
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