What Is the Service Life Standard of Industrial Hot Runner Thermocouples

Standard industrial-grade thermocouples have well-established service life criteria in the hot runner supporting accessory business. These standards are broken down into three categories based on various production conditions: normal working life, high-load working life, and harsh environment service life. Qualified brand hot runner thermocouples may achieve a stable service life of 10 to 14 months under typical conventional working conditions, which include long-term stable operation within 180°C to 280°C, continuous daily production for 8 to 10 hours, and clean raw materials without filling additives. No open circuit, short circuit, or evident aging breakdown occurs during this cycle, and the temperature measurement error stays within ±0.8°C.

The service life will be proportionately reduced under high-load continuous production settings, such as 24-hour uninterrupted operation, frequent mold opening and shutting, and frequent temperature adjustment. The effective stable service term typically lasts between six and nine months. Thermocouple core wires will eventually develop thermal fatigue, temperature drift will become noticeable, and response sensitivity will decline when this time limit is exceeded, necessitating routine calibration or prompt replacement.

The service life criterion is further lowered to three to five months in difficult production conditions, such as glass fiber reinforced plastics, flame-retardant modified materials, and long-term ultrahigh temperature working above 300°C. The probe and internal structure would be continuously eroded by strong abrasion and corrosive gas, hastening the attenuation of performance. Even though the thermocouple can still display temperature data normally after the industry-standard service life, its internal thermoelectric performance has been unsteady, and there are still unidentified production dangers.

Rather than using expired products until they completely fail, manufacturers should set up a regular replacement system in compliance with service life criteria. The precise temperature control state of the hot runner system can always be maintained, unanticipated shutdown losses can be minimized, and injection molding production can continue to run efficiently and steadily throughout the year with timely replacement before it reaches the service life limit.