The system that establishes the relationship between a measuring device and a traceable reference standard. Calibration may include detecting, correlating, reporting or eliminating discrepancies in the accuracy of the measuring instrument.
A standard of known accuracy. The standard should be traceable to the national standard of the country concerned. In the United States that is the National Institute of Standards and Technology (www.nist.gov).
Gage Repeatability and Reproducibility. The combined effects of measuring systems repeatability and reproducibility:
The change in bias over the operating range of a measuring instrument.
See Measurement Systems Variation.
Measurement Systems Analysis 

The analysis of a measuring system to determine the amount of variation in the measurement. The amount of variation in the measuring system is often overlooked, but is often a significant component of the observed variation.
The types of measurement error can be categorized into: bias, linearity, stability, repeatability, reproducibility.
Measurement Systems Capability 

Short term estimate of the Measurement System Variation.
Measurement Systems Variation 

See Gage R&R
See Measurement Systems Analysis
See Number of Distinct Categories
Number of Distinct Categories 

A measure of the number of distinct (nonoverlapping) categories that can be distinguished by a measuring system:
Precision to Tolerance Ratio 

The ratio of the precision of the measuring system to the total variation:
Precision/Total Variation Ratio 

The ratio of the precision of the measuring system to the total variation:
See Precision to Tolerance Ratio
See Precision/Total Variation Ratio
In Measurement Systems Analysis, the variation when one person measures the same item several times, using the same measuring equipment.
In Measurement Systems Analysis, it is usually taken to be the variation in the average measurement that occurs when two or more people measure the same items using the same measuring technique. It may also be used to compare different measuring devices at different locations.
Smallest readable unit of a measuring instrument.
With measurement, the change in bias over time. More generally the degree to which the parameters of a process are stable over time.
