Verification regulations for bimetallic thermometers

Bimetallic thermometer is a widely used temperature measuring instrument in industries, scientific research and other fields. To ensure the accuracy and reliability of its measurement results, regular calibration is crucial. This regulation aims to standardize the calibration operation of bimetallic thermometers, ensuring that the calibration process is scientific, fair, and accurate.

Preparation before verification

1. Verification environment: Select an environment with stable temperature, no strong vibration or magnetic field interference for verification. The room temperature should be maintained at (20 ± 5) ℃ and avoid direct sunlight.

2. Calibration equipment: Prepare necessary calibration equipment such as standard thermometers, constant temperature baths, brackets, and connecting wires. Standard thermometers should be calibrated by the higher-level metrology institution and have valid calibration certificates.

3. Tested thermometer: Confirm that the appearance of the tested thermometer is intact, without obvious damage or deformation. Check that the identification is clear and that the range and division values meet the calibration requirements.

Verification steps

1. Installation and calibration: Fix the tested thermometer vertically on the bracket, ensuring that its temperature sensing element is in the center position of the constant temperature bath. Connect the connecting wire and adjust the temperature of the constant temperature bath to the midpoint of the range of the tested thermometer. After stabilizing for 10 minutes, record the readings of the tested thermometer and the standard thermometer.

2. Temperature point calibration: Select at least 5 temperature points within the range of the verified thermometer for calibration. After stabilizing at each temperature point for 10 minutes, record the readings of the tested thermometer and the standard thermometer.

3. Error calculation: Based on the recorded readings, calculate the indication error of the tested thermometer at each temperature point. The indication error should not exceed the allowable error limit.

Determination of Verification Results

1. Qualification judgment: If the indication error of the verified thermometer at all verification temperature points does not exceed the allowable error limit, it is judged as qualified.

2. Unqualified judgment: If the reading error of the verified thermometer at any verification temperature point exceeds the allowable error limit, it is judged as unqualified.

Verification records and reports

1. Verification record: Detailed records of the environmental temperature, constant temperature bath temperature, readings of the verified thermometer and standard thermometer during the verification process.

2. Verification report: Based on the verification records, prepare a verification report. The report should include basic information, calibration process, calibration results, and conclusions of the verified thermometer.

Precautions

1. Operating standards: During the verification process, strict adherence to the regulations should be followed to avoid errors caused by misoperation.

2. Safety precautions: During the verification process, attention should be paid to electrical safety to avoid accidents such as short circuits and electric shocks.

3. Maintenance and upkeep: Regularly maintain and upkeep the calibration equipment to ensure that it is in good condition.

Verification cycle and validity period

1. Calibration cycle: The calibration cycle of bimetallic thermometers is generally one year.

2. Validity period: The bimetallic thermometer that has been verified as qualified shall be used within the validity period, which is generally one year from the date of self inspection and qualification.

This regulation aims to ensure the accuracy and reliability of bimetallic thermometers, providing accurate temperature measurement data for industries, scientific research, and other fields. In practical operation, the calibration should be strictly carried out in accordance with the regulations to ensure the accuracy and impartiality of the calibration results.