Meaning
Calibration errors occur when the output of a measurement device changes over time despite the input remaining constant. In a moulding environment, sensor drift in thermocouples or pressure transducers leads to a loss of process control as the machine begins to act on inaccurate data. This phenomenon is often caused by thermal fatigue or the buildup of resin residue on the sensor face.
Accuracy Decay
Gradual shifts in the signal can be difficult to detect during a single production run. Because sensor drift happens slowly, the operator may adjust the machine settings to compensate for what appears to be a material change. This results in a process that is technically within specification but physically unstable.
Measurement Error
Electrical noise or mechanical wear can cause the zero point of a transducer to move. When sensor drift affects the cavity pressure reading, the machine may fail to pack the part correctly, leading to dimensional errors. Periodic recalibration against a known standard is required to maintain the integrity of the data.
Output Shift
Total loss of accuracy occurs if the device is not maintained or replaced at the end of its service life. Reliable production depends on the ability to trust the readings from every sensor drift source in the system.
