Measurement is the set of operations having the object of determining the value of a quantity. Metrology is the field of knowledge concerned with measurement and include both theoretical and practical problems with reference to measurement, whatever their level of accuracy and in whatever fields of science and technology they occur. (Source: BS 5233:1975). Metrology can also be defined as the science of measurement.

	Units of measurement and their standards (their establishment, reproduction, conservation and dissemination)
	Measurements (their methods, execution, estimation of their accuracy etc.)
	Measuring instruments (their properties examined from the point of view of their intended purpose)
	Observers (their capabilities with reference to making measurements, e.g. reading of instrument indications.

	Legal metrology is that which is required by Law (mandatory) and seeks to protect the public against inaccuracy in trade. (Examples - the volume of petrol purchased at the pump or the weight of prepackaged flour.
	Scientific metrology is all other forms of measurements.

Benefits of the Bureau's metrology programme

	Use of the appropriate measuring devices where measurements are to be used to compute revenues.
	Ensure fair trading in a wide variety of commodities.
	Ensure that units of measurement used in Jamaica are the same as elsewhere in the world
	Ensure that industry has access to the true units of measurements thus preventing waste and substandard products
	Ensure that there is proper base for the settlement of measurement disputes.

Calibration is the comparing of a measurement device (an unknown) against an equal or better standard. A standard in a measurement is considered the reference; it is the one in the comparison that is taken to be the more correct of the two. One calibrates to find out how far the unknown is from the standard.