Thermocouple aging is gradual and hidden, but early signs can be identified to prevent sudden failures.
Increasing temperature drift is the most typical symptom. If the set value must be raised gradually to maintain the same quality, the sensor is drifting.
Unstable or jumping readings indicate cable aging, insulation degradation or poor contact.
Longer heating time to reach setpoint suggests reduced sensitivity and response speed.
Frequent heater burnout or abnormal power consumption implies thermocouple control failure.
Inconsistent part quality between cavities without parameter changes points to aging of individual thermocouples.
Regular calibration can quantify drift and determine replacement timing.
Comparing temperature differences between similar zones helps identify abnormal sensors.
Preventive replacement based on service life is effective in high-cavity and continuous production.
Early detection of thermocouple aging avoids unexpected downtime and mass scrap.
