Self-calibration is a process performed by a user for the purpose of making an IM&TE instrument or system ready for use. The process may be required at intervals such as every power-on sequence; or once per shift, day, or week of continuous operation; or if the ambient temperature changes by a specified amount. Once initiated, the process may be performed totally by the instrument or may require user intervention and/or use of external calibrated artifacts. The usual purpose is accuracy enhancement by characterization of errors inherent in the measurement system before the item to be measured is connected. Self-calibration is not equivalent to periodic calibration (performance verification) because it is not performed using a calibration procedure and does not meet the metrological requirements for calibration. Also, if an instrument requires self-calibration before use, then that will also be accomplished at the start of a calibration procedure. Self-calibration may also be called normalization or standardization.
Compare with: calibration (2.B) Contrast with: calibration (1)