recalibration

Recalibration is the process of verifying and readjusting the output of a measurement instrument or system to align with a reference standard or true value. It is a routine activity in metrology and quality assurance, performed to compensate for drift, bias, wear, or environmental effects that occur over time.

The scope of recalibration covers a wide range of devices and systems, including laboratory instruments, manufacturing gauges, medical devices, environmental sensors, and consumer electronics. It may be performed after maintenance, following repairs, or on a scheduled basis. Recalibration differs from initial calibration in that it is typically used to maintain accuracy between calibrations and to confirm continued traceability to recognized standards.

Procedure generally involves comparing instrument readings against known reference values, determining any deviation, applying corrective adjustments (hardware or software), and then re-testing to verify that results meet specified tolerances. Documentation is essential: calibration records, certificates of traceability, and an uncertainty budget should accompany every recalibration to demonstrate compliance with standards.

Environmental and operational factors such as temperature, humidity, vibration, aging components, and usage patterns can influence drift and bias. Recalibration strategies may be event-driven (after impact or repair) or time-driven (regular intervals). The goal is to maintain accuracy, ensure data integrity, and minimize downtime or cost associated with measurement error.

Examples include recalibrating weighing scales, gas analyzers, coordinate measuring machines, thermometers, and process control sensors. In broader terms, recalibration can also refer to updating perceptual or computational models in response to new data or altered conditions.