Metrology (from Greek μέτρον "measure" + λόγος "thought; reason") — the science of measurements, methods and means of ensuring their uniformity, and ways to achieve the required accuracy. The subject of metrology is the extraction of quantitative information about the properties of objects with specified accuracy and reliability; the regulatory basis for this is metrological standards.
Uniformity of measurements — a state of measurements when results are expressed in accepted units, and measurement errors are accepted with a given probability. Uniformity of measurements is necessary for comparing measurement results conducted in different places, at different times, using different methods and measuring instruments. The results must be the same regardless of the methods and instruments used. Measurement accuracy means the maximum closeness of their results to the true value of the measured quantity.
