How to Maintain Thermocouples for Extended Service Life?

Regular maintenance extends thermocouple probe service life by 2 to 3 times compared to unmaintained systems. A systematic maintenance program covering daily visual checks, weekly cleaning, monthly calibration, and quarterly full disassembly inspections ensures long-term reliability. Daily Inspection Daily inspection should check the temperature controller display value every shift, observing whether there is random jumping, slow temperature rise and frequent over-temperature alarm. Check whether the lead is worn. Before starting production every day, check whether the thermocouple connector is loose, whether the wire is damaged, and whether the temperature display is normal. Early detection of abnormal readings prevents production of defective parts. Weekly Maintenance Weekly maintenance includes disassembly and surface cleaning of accessible nozzle tip thermocouples. Remove any plastic residue, carbon deposits, or oxidation from the probe surface. Check the fastening degree of thermocouple threads and insertion depth every half month, re-lock loose parts in time to ensure close fitting. Inspect leads, verify compression, and check for discoloration. Monthly Calibration Monthly calibration with a multimeter should check heater resistance values and thermocouple continuity to avoid aging components operating with hidden defects. Use a professional temperature calibrator to compare the displayed temperature with the actual temperature. If deviation exceeds acceptable limits, perform calibration adjustment or replace the sensor. Quarterly Full Disassembly Inspection Every three months, conduct a full performance inspection. Comprehensive inspection of wiring terminals in the temperature control box should be performed. Check for moisture intrusion and dry the connector if necessary. Replace worn insulation and inspect sheath condition. Annual Performance Testing After one year of continuous use, all thermocouples on the mold need to carry out full temperature response test and precision error detection. For high-duty molds, annual replacement of all thermocouples is recommended to restore OEM-level accuracy. Temperature drift exceeding ±2°C from the 200°C to room temperature three-cycle aging test indicates replacement is required. Long-Term Storage Store spare thermocouples in dry constant-temperature cabinets to prevent sheath rust and wire oxidation before use. Proper storage ensures that replacement sensors perform to specification when needed.