I. Preparation Before Calibration
Environmental Requirements: The room temperature should ideally be between 15-35℃, humidity not exceeding 85%, and direct sunlight or strong winds should be avoided.
Tools Required: A standard thermometer (such as a mercury thermometer or a high-precision digital thermometer) is needed as a reference.
II. Calibration Methods
1. Ice-Water Mixture Method (for measuring low temperatures): Mix pure water and ice in a 1:1 ratio. When the temperature stabilizes at 0℃, immerse the probe completely for 30 seconds.
If the displayed value deviates from 0℃ by more than ±0.1℃, adjust the calibration parameters according to the instruction manual.
2. Boiling Water Method (for measuring high temperatures): Boil water under standard atmospheric pressure. When the water temperature drops to 100℃, insert the probe.
In high-altitude areas, the boiling point temperature needs to be corrected according to the altitude (the boiling point decreases by approximately 1℃ for every 300 meters increase in altitude).
3. Comparison Method (for actual use): Use a mercury thermometer or a certified medical electronic thermometer as a reference, simultaneously measure the axillary temperature three times and take the average.
If the difference exceeds 0.2℃, adjustment is required through the device calibration procedure.
III. Post-Calibration Verification
Stability Test: After calibration, measure again after a while to see if the result is stable.
Error Calculation: Subtract the standard temperature from the displayed temperature. If the error exceeds the allowable range (e.g., ±0.5℃), the thermometer should be retired.
IV. Precautions
Calibration Frequency: It is recommended to calibrate once a year for ordinary households; for medical or industrial equipment, shorten the cycle as needed.
Operating Procedure: The probe must be completely immersed in the standard temperature source, avoiding contact with the container wall.
Result Interpretation: If a large deviation still exists after retesting, it is recommended to contact the manufacturer or a metrology institution for professional calibration.
