Measurement Stability
Metrological errors characterized by the gradual change in the output of a standard or a sensor over time can compromise the accuracy of a whole system. Reference drift occurs even when environmental conditions like temperature and pressure are held constant. This slow shift is measured against a primary standard that is known to be more stable than the device under test.
Environmental Influence
Temperature fluctuations often cause the internal voltage or resistance of a reference component to fluctuate. While some of this change is temporary, extreme conditions can lead to permanent reference drift. Proper shielding and thermal insulation help to minimize these external effects on the precision of the circuit.
Aging Mechanism
Chemical changes in a semiconductor or mechanical fatigue in a ceramic substrate lead to subtle variations in electrical properties. In many precision instruments, reference drift is highest during the first few hundred hours of operation. Stable performance is usually achieved after a period of seasoning.
Compensation Strategy
Software algorithms can track the expected rate of change and apply corrections to the measurement data. Regular calibration checks against a known external source are necessary to verify that the reference drift has not exceeded the specified tolerance. If the drift becomes too large, the reference component must be replaced or the entire device must be readjusted.
