🔧 I. Preparation before calibration
Environmental requirements: Place the equipment in an indoor environment of (23±5)℃ and humidity ≤85% for 2 hours to avoid the influence of temperature differences.
Tools required:
High-precision infrared thermometer (accuracy ±0.5℃, such as Fluke 62 Max+)
Contact thermocouple thermometer (K type, accuracy ±0.3℃)
Standard heating plate (no scratches, oxide layer)
Data recording sheet or mobile recording tool
Contact thermocouples are recommended for final determination. Infrared thermometry is suitable for rapid inspection but is easily affected by surface emissivity.
📏 II. Calibration steps (dual methods in parallel, mutual verification)
✅ Method 1: Using a contact thermocouple thermometer (recommended as the reference method)
Place the thermocouple probe firmly against the center of the heating plate surface to ensure good thermal contact.
Set the target temperature of the fusion welder to 210℃ (common welding temperature for PE pipes). After the temperature stabilizes (usually 15–30 minutes), record the temperature value every 30 seconds, for a total of 10 consecutive measurements.
Calculate the average value and compare it with the set value; the deviation should be ≤ ±7℃.
Repeat the test at 5 points (four corners and center) to assess temperature uniformity (difference between points ≤ 5℃).
If the deviation exceeds the limit, enter the equipment calibration mode and adjust the PID parameters or send it back for repair.
✅ Method 2: Using a high-precision infrared thermometer (suitable for rapid detection)
Set the emissivity: Set the emissivity of the infrared thermometer to 0.95 (typical value for metal heating plates with Teflon coating).
Control the measurement distance to 15–30cm, perpendicularly aligned with the heating plate surface.
Similarly, select 5 measurement points (center + four corners), measuring each point 3 times and averaging the results.
Record the measured temperature; the maximum deviation should not exceed the set value ±7℃.
Avoid reflective areas and prevent sunlight or strong light sources from interfering with the readings.
Infrared measurement is convenient but requires attention: oxidation, oil stains, and coating peeling can significantly affect measurement accuracy.
⚙️ III. Post-Calibration Operation Recommendations
Mark Calibration Date: Mark the calibration date on the equipment or in the management log.
Set Calibration Cycle: Industrial-grade equipment is recommended to be calibrated every 3 months. For high-frequency use or operation in harsh environments, this can be shortened to monthly.
Establish Traceability Records: Preserve original data to support project acceptance and quality audits.
