Burn in Hours That Remove the Steepest Early Drift
Thermal burn-in under active electrical bias removes early non-linear drift, locking in long-term calibration stability before sensors reach the field.
Piezoresistive Transducer Drift
Sensor Instability
Unintended baseline change in silicon or thin-film strain sensing elements occurs independently of applied mechanical force over extended timeframes. The occurrence of piezoresistive transducer drift originates from lattice defect migration, structural strain relaxation or moisture absorption within the transducer matrix. This uncommanded signal movement degrades measurement accuracy and zero-point stability in pressure and force sensors.
The scope of this drift covers non-input baseline changes, excluding linear temperature coefficient effects that are dynamically compensated.
Strain Relaxation
Diffused silicon strain elements rely on crystal lattice deformation to alter electrical resistivity under mechanical load. Over prolonged operation, internal residual stresses generated during semiconductor doping, chip bonding or substrate packaging undergo localized creep relaxation. This micro-structural rearrangement alters the baseline piezoresistive coefficient of the silicon bridge arms.
Moisture diffusion through protective gel encapsulation further alters dielectric surface charge and mechanical loading, accelerating zero-offset movement during long-term field deployment.
Measurement Error
Uncontrolled shift in bridge resistance distorts true pressure or force measurements. As piezoresistive transducer drift accumulates over months of operation, calibrated scale factors degrade, requiring recalibration to restore specified measurement accuracy.
Verification Limit
Metrological specifications limit maximum allowable drift to fractions of a percent of full-scale output per year. Sensor datasheets define long-term stability under reference temperature and atmospheric conditions. Calibration certificates document initial zero offset and span stability measurements across pre-defined environmental testing intervals.