Based on your previous focus on LVDT zero point settings and the impact of the zero point on hot runner operation, the following methods can be used to determine if the LVDT zero point is offset:
Mechanical Position Verification: Fully close the hot runner needle valve and confirm that the valve needle is tightly against the gate reference surface. If the displacement value displayed by the LVDT system is not 0 at this time, the zero point has been offset.
Output Signal Detection: Use a multimeter to monitor the output voltage of the LVDT when the needle valve is at the zero position. If the measured voltage deviates significantly from the 0V reference value, it indicates that the electrical zero point has drifted.
Production Phenomenon Inference: If gate leakage or insufficient valve needle opening stroke occurs during hot runner production, and no mechanical jamming is confirmed, it can generally be determined that the LVDT zero point is offset.
Full Stroke Verification: Manually drive the needle valve to complete the preset full stroke. If the total displacement displayed by the system deviates from the actual mechanical stroke by more than 1%, it indicates that the zero point reference has shifted overall.
