Based on your previous focus on the determination and correction of LVDT zero-point deviation in hot runner systems, the following characteristics can be used to determine if an LVDT needs correction:
Mechanical Position Mismatch: When the needle valve is fully against the gate reference surface, the system displays a displacement value that is not 0, with a deviation exceeding 0.01mm. The zero point has shifted and needs correction.
Abnormal Output Signal: At zero position, the LVDT output voltage deviates significantly from the 0V reference value and is outside the sensor's linear range, requiring correction.
Inaccurate Full Stroke Data: After driving the needle valve to complete the preset full stroke, the system displays a total displacement that deviates from the actual mechanical stroke by more than 1%, indicating an overall shift in the zero-point reference, requiring correction.
Abnormal Production Conditions: During hot runner production, gate leakage and insufficient needle valve opening stroke occur. After investigation confirms no mechanical jamming, the root cause is zero-point deviation, requiring correction.
Failed Hot Runner Verification: After the hot runner is heated to operating temperature and held at that temperature, a significant zero-point drift occurs, failing to match the actual position after thermal expansion, requiring correction.
Periodic calibration due. Accuracy calibration should be performed every 3-6 months according to industry standards. If linearity or repeatability indicators are found to be out of range, timely correction is required.
Would you like me to prepare a quick checklist for whether a hot runner LVDT needs correction? It can help you determine this in 1 minute.
