Yes, calibration should be performed immediately after replacing the hot runner temperature sensing wire. Delay is not recommended. Calibration should be performed as soon as installation is complete and the wiring is checked to ensure accurate temperature control and stable injection molding process.
I. Why is timely calibration necessary
Avoid operating with faulty sensors: Even if the new temperature sensing wire meets the PT100 standard, there are still slight differences between individual wires (e.g., ±0.5℃). If it is put into production without calibration, it may cause localized overheating or underheating, leading to problems such as material degradation and insufficient filling.
Prevent misjudging process abnormalities:An uncalibrated sensor may display incorrect temperatures, causing operators to incorrectly adjust heating parameters, masking the true problem and increasing the scrap rate.
Ensure system compatibility: Hot runner controllers typically optimize PID parameters based on historical data from the original sensor. After replacement, recalibration is necessary; otherwise, the temperature control response speed and stability will be affected.
II. Recommended Calibration Timing
|
Scenario |
Recommended Calibration Time |
|
Routine Maintenance & Replacement |
Calibrate immediately after installation; complete signal verification before power-on. |
|
Emergency Fault Replacement |
Calibration must be completed after troubleshooting and before trial molding. |
|
Precision Molding Applications |
Multi-point calibration is mandatory after replacement; it cannot be skipped. |
Best Practice: Incorporate "Replacement → Calibration → Verification" into the Standard Operating Procedure (SOP) to form a closed-loop management system.
III. Handling Recommendations for Special Circumstances
If Calibration is Temporarily Unavailable: | Use a multimeter to measure resistance to confirm no open/short circuits, and perform preliminary comparison using an infrared thermometer (deviation ≤ ±3℃). This is only for temporary operation, not exceeding one shift. A formal calibration must be performed subsequently.
During Batch Replacement: | It is recommended to replace and calibrate channel by channel to avoid simultaneous failure at multiple points leading to system outage.
IV. Post-calibration Verification Key Points
Verify key temperature points (e.g., 200℃, 250℃) using a temperature calibrator or multi-point comparison method.
Start the heating program and observe whether the temperature curve rises smoothly.
Monitor the melt flow state during the trial molding stage to confirm that there are no defects caused by temperature deviations.
Reminder: Some high-end systems support the "one-click calibration" function, which can automatically complete the calibration through software, improving efficiency and consistency.
