How does drift differ from other types of instability?

Drift is characterized as a gradual change in the measurement of an instrument over time, which often occurs under stable conditions. This gradual change can often be anticipated based on historical data related to the instrument and its environment, making drift more predictable compared to other types of instability such as random noise or sudden shifts that can occur in a measurement system.

Understanding this predictability is crucial for calibration technicians, as it allows them to anticipate adjustments that may need to be made to maintain accurate measurements. This predictability differentiates drift from more chaotic forms of instability, where the changes could be abrupt and random, making them difficult to manage or forecast.

Additionally, while temperature affects instruments and can contribute to errors or variations, drift itself is not defined by temperature variations but by the consistent trend of measurement changes over time, regardless of the operational temperature. Drift affects the accuracy of measurements because it introduces bias in readings, but it does not inherently affect precision unless it leads to systematic errors that alter the reproducibility of results.