Temperature sensor calibration is achieved by comparing the measured values of the sensor with standard reference values, adjusting its output parameters, and ensuring measurement accuracy. The main solution is to solve the problem of decreased accuracy of sensors due to production deviation and long-term use. Through standard equipment verification and correction of measurement deviation, the stability and reliability of temperature control are guaranteed.
Calibration of temperature sensors is a crucial step in ensuring accurate and reliable measurement results, especially in fields such as industrial control and meteorological monitoring that require high precision.
Preparation before calibration:
Determine calibration requirements
Accuracy requirement: Determine the allowable error range (such as ± 0.1 ℃, ± 1 ℃) based on the application scenario (such as laboratory, industrial site).
Temperature range: Clearly define the temperature range (such as -20 ℃~100 ℃) within which the sensor needs to be calibrated.
Calibration point selection: Select 3-5 key points uniformly within the temperature range (such as low temperature, medium temperature, high temperature), or focus on selecting according to the usage scenario (such as selecting 35 ℃, 37 ℃, 40 ℃ for human body temperature calibration).
calibration method
Fixed point calibration: Using the phase transition point of the substance (such as the water triple point 0.01 ℃) as a reference, calibrate the sensor through pure substance phase transition temperature.
Comparative calibration: Place the sensor and standard in a constant temperature bath at the same time, record the measurement values of multiple temperature points, and fit the calibration curve through mathematical methods.
Blackbody furnace calibration: suitable for high temperature sensors (>300 ℃), correcting emissivity errors by comparing the radiation source with a standard optical pyrometer.
Common Problems and Solutions
Reasons for slow sensor response: large thermal capacity or poor contact.
Solution: Extend the stability time or improve the installation method (such as using thermal conductive silicone grease).
Nonlinear reasons for errors: sensor aging or changes in material properties.
Solution: Segmented calibration or replacement of sensors.
If the calibration is still poor, check the accuracy of the data acquisition system or confirm whether the standard equipment is within its validity period.