Meaning
Unintended change in the baseline reference point of a sensor or measurement system during a production run. Frequent monitoring of the zero offset shift prevents the collection of false pressure data from the mould cavity. Errors accumulate when the sensor does not return to its starting voltage between cycles.
This drift compromises process control and can lead to the production of out-of-tolerance parts.
Data Integrity
Reliability of the process monitoring system depends on the stability of the sensor baseline. If a zero offset shift occurs in a cavity pressure sensor, the machine may incorrectly trigger the switchover from fill to pack. This leads to parts that are either overpacked or underfilled.
Quality control systems use automatic zeroing functions to mitigate this risk.
Thermal Drift
Changes in the ambient temperature of the mould or the machine frame can cause the sensor signal to wander. Because many transducers are sensitive to heat, a zero offset shift is common during the start-up phase of a run. Sophisticated controllers use software compensation to track these changes and adjust the baseline in real time.
This ensures that the pressure readings remain consistent as the tool reaches thermal equilibrium. High precision moulding depends on this stability.
Sensor Maintenance
Physical damage or the buildup of resin residue on a sensor face can also trigger this error. Regular inspection prevents the zero offset shift from causing undetected part defects.
