According to the National Metrological Verification Regulation JJG 351-1996, "Verification Regulation for Working Base Metal Thermocouples," the standard verification cycle for industrial base metal thermocouples is one year. This is the fundamental calibration cycle required for hot runner applications, and it meets the ISO 9001 quality management system's traceability standards.
Dynamic Adjustment Cycle under Different Operating Conditions: If the thermocouple is used for extended periods of time in harsh conditions such as temperatures above 800°C and the presence of corrosive plastic volatile gases, the calibration cycle should be reduced to 3-6 months to avoid thermoelectric drift, which can lead to inaccurate temperature measurements.
For crucial temperature measurement locations used in high-end precision injection moulding applications such as automotive and medical equipment, a 6-month calibration cycle is advised to assure consistent product moulding precision.
If the thermocouple operates for extended durations in a low-temperature, clean environment below 400°C, and historical calibration data reveals negligible drift, the calibration cycle can be extended to 12 months while still meeting metrological management standards.
Dynamic Optimisation Rules: After each calibration, note the thermocouple's thermoelectric potential deviation. If the deviation reveals a fast increase trend, the calibration cycle should be cut short immediately, and the reason of thermocouple deterioration explored. If the deviations in three consecutive calibrations are all far below the permitted error range, the calibration cycle can be suitably prolonged, as long as it remains within the constraints of the quality system, balancing accuracy and maintenance costs.
This calibration cycle rule is entirely adjustable to the application situations of Husky hot runner temperature control systems, meeting national metrological compliance criteria while also accommodating the actual needs of various production conditions.
