Repetability

Repetability is a less common spelling variant of repeatability, a term used in measurement science to describe how consistently a measurement procedure can produce the same result under identical conditions. In many contexts, repeated measurements with the same instrument and operator on the same item should yield nearly the same value if the system has high repeatability. Because repeatability is the standard term, some sources use repetability as a historical or regional variant, but the meaning is essentially the same.

In measurement systems analysis, repeatability refers to the within-method or within-run variation: the variation in measurements caused by the measurement process itself when conditions are kept constant. This contrasts with reproducibility, which captures variation across different operators, different instruments, or different environments. Quantifying repeatability typically involves statistical measures such as the standard deviation or range of repeated measurements, often expressed as within-run precision. In practice, a high-precision system shows low repeatability variance, implying that repeated measurements cluster tightly around a common value.

Factors that affect repeatability include instrument resolution and calibration, operator technique, how the part is positioned, fixture stability, and environmental conditions such as temperature and vibration. Improving repeatability usually involves regular calibration and maintenance, standardized measurement procedures, better fixtures or jigs to minimize positioning errors, and training to ensure consistent technique.

See also: repeatability and reproducibility, measurement system analysis, Gage R&R, precision, accuracy.