I. Full-Range Accuracy Deviation Verification: Measure the signal generator's actual output values at each of the 10%, 25%, 50%, 75%, and 100% full-range settings using a reference process calibrator with an accuracy class ≥ ±0.01%.
The equipment's nominal accuracy range must be used to control the output deviation at all calibration sites. The variation should be < ±0.05%FS for traditional industrial-grade equipment and ≤ ±0.02%FS for high-precision models, with no points going over the tolerance.
Thermocouple millivolt analogue output deviation ≤ ±1μV and Pt100 RTD analogue output deviation ≤ ±0.01Ω are specific verifications for thermal signals that fully meet the hot runner temperature control channel's calibration accuracy standards.
II. Zero Point and Stability Verification: Verify the zero-point output value after the apparatus has remained motionless for half an hour. There must be no zero-point drift or rebound, and the zero-point offset must be less than 0.02% of the range.
The apparatus operated continuously for an hour, collecting output data from critical calibration points every ten minutes. There shouldn't be any instability brought on by persistent deviation over time, and the drift amount within an hour shouldn't be more than 0.03% of the range.
After tapping the equipment case, the output fluctuation duration was ≤2 seconds, with no aberrant leaps, according to a slight vibration test.
III. Verification of Environmental Adaptability
Temperature Sensitivity Test: The apparatus was operated at 60°C and -10°C for 30 minutes each. There should be no abrupt increase in temperature drift and the drift amount should not surpass 120% of the drift at room temperature.
Multi-channel Synchronisation Verification: There was no inter-channel synchronisation drift deviation, and all channels' synchronisation deviation was less than 0.01 seconds.
IV. Verification of Process Scenarios
The restored signal generator was used to calibrate all of the hot runner's temperature control channels. Following two hours of continuous injection moulding production, there were no drift-related process flaws like uneven filling or localised overheating, and product weight fluctuation was kept within 3%.
For three consecutive production shifts, the discrepancy between the temperature displayed and the temperature of the temperature control channels was monitored. There were no erratic swings and the difference stayed constant within ±1°C.
The drift can be deemed fully rectified and the equipment can resume regular usage once all verification items satisfy the requirements.
