I. Judgement of Irreversible Accuracy Failure:
Replacement is necessary if the full-range output deviation is more than five times the device's nominal accuracy and, even after three professional calibrations and core component replacements, the accuracy cannot be brought back to the factory acceptable range.
Thermocouple millivolt analogue output deviation surpasses ±20μV, Pt100 RTD analogue output deviation exceeds ±0.2Ω, and all calibration and repair techniques are unsuccessful; replacement is necessary due to completely inaccurate thermal signal output.
The frequency output deviation is greater than ±20 ppm, and even with the frequency correction factor adjusted and the crystal oscillator replaced, the calibration accuracy requirements of the hot runner temperature control channel are not met, necessitating a replacement.
II. Judgement for Irreversible Hardware Damage:
Replacement is necessary if the device's power module, main control board, output amplifier board, and other essential hardware exhibit significant burnout, severe circuit board carbonisation, and repair expenses above 60% of the cost of a brand-new device with the same specifications.
Replacement is necessary if the device sustains significant physical damage from a drop, including total internal structure deformation and failure of all multi-channel outputs, making it irreparable. The equipment's essential parts have been entirely withdrawn, and it is impossible to get replacement parts with the same requirements. After a malfunction, replacement is considered necessary because repair is not viable.
III. Total Stability Loss Determination
The drift surpasses 0.5% of the range after 15 minutes of continuous operation. The drift keeps rebounding even after all ageing parts have been replaced, making stable operation impossible and necessitating replacement.
Long-lasting, erratic output fluctuations are caused by a slight vibration of the device casing. A possible issue with the internal circuitry is extensive faulty soldering, which calls for replacement because it cannot be fixed by repeated repairs.
The thermal drift coefficient surpasses ±0.2%/℃ under normal operating settings at room temperature, rendering it totally unsuitable for industrial situations and necessitating replacement.
IV. Life Cycle and Compliance Determination: The equipment's intended lifespan of eight to ten years has been reached. Hardware is severely ageing overall, necessitating replacement due to frequent malfunctions and fixes that occur more than once a month.
The existing hot runner calibration requirements of precision injection moulding manufacturing lines are entirely unmet by the equipment's accuracy level. Replacement would be necessary since upgrading and retrofitting would cost more than 70% of the cost of a new piece of high-precision equipment.
Even if the equipment operates normally, it must be replaced with a model that conforms with the most recent metrological specifications if it cannot be linked to the most recent standards and does not fulfil ISO system audit requirements.
In order to avoid problems that could result in an incorrect hot runner temperature control calibration and a batch of faulty injection-molded products, the equipment should be changed right away if any of these conditions are met.
