Based on our previous focus on the typical lifespan of thermocouples in hot runner injection molding (1-3 years) and the risk of temperature control inaccuracies after this period, the following typical symptoms will appear after a thermocouple reaches the end of its lifespan:
Temperature accuracy drift: The deviation between the displayed temperature and the actual temperature continues to widen, far exceeding the normal allowable range of ±2℃, and cannot be corrected by routine calibration.
Signal instability: Temperature readings fluctuate frequently, exhibiting irregular numerical fluctuations, and occasionally displaying abnormal values beyond the range.
Slower response speed: After changes in hot runner temperature, the delay in thermocouple feedback data becomes significantly longer, making it impossible to capture temperature fluctuations in real time.
Physical deterioration: The outer stainless steel sheath shows oxidation, peeling, and cracks; the internal thermocouple wires age and break, directly leading to open-circuit temperature measurement failure.
If these symptoms appear, the thermocouple should be replaced promptly to avoid production failures such as hot runner overheating caused by inaccurate temperature measurement.
