Prepare for Calibration
Confirm that the repaired thermocouple circuit resistance and insulation resistance meet specifications, that the terminals are tightly crimped with no loose connections, and that the thermocouple sensing end is completely in contact with the hot runner temperature measurement point.
Allow the Husky thermostat and hot runner system to stand in the calibration environment for 30 minutes to allow the internal components to achieve thermal balance with the surrounding environment, preventing reading drift from compromising the accuracy of the calibration findings.
Create a metrologically calibrated Class II standard thermocouple with a low-potential DC potentiometer with an accuracy of 0.02. Confirm that the accuracy of the standard equipment is greater than one-third of the allowed error of the thermocouple being calibrated.
**Multipoint Temperature Field Data Acquisition**
Choose three typical temperature points: 20%, 50%, and 80% of the thermocouple's range. Gradually increase the temperature from low to high, maintaining a constant temperature at each stage for at least 30 minutes. The temperature field change should be ≤0.2℃/min.
A standard-calibrated-standard forward and backward cyclic reading approach was employed, with at least four measurements obtained at each temperature point. The conventional thermocouple's temperature values and the Husky thermostat's displayed temperature were recorded, and the indication error was determined for each point.
To configure error correction parameters, navigate to the Husky thermostat's "Advanced Calibration" menu and select the multi-point linear compensation parameter setting interface. Enter the error correction values for three temperature points sequentially to generate a full-temperature-range linear compensation curve.
Confirm that the cold junction compensation settings precisely match the recorded ambient temperature at the wiring point, preventing any additional system faults caused by cold junction temperature drift.
Closed-Loop Verification After Calibration: Once the parameter adjustments are complete, start the thermostat's PID self-tuning program to adjust the system to the new linear compensation characteristics and optimise the temperature control curve.
Run at a steady temperature for two hours. Randomly select numerous temperature points from the whole temperature range for comparison testing with the conventional thermocouple. Check that the full-temperature-range measurement deviation is ≤ ±1℃, the temperature fluctuation is ≤ ±1℃, and there is no drift or leap. Calibration has completed.
This calibration technique is totally compatible with conditions after Husky hot runner thermocouple repair and may completely eliminate temperature measurement aberrations caused by the repair, ensuring the system's long-term stability.
