Measurement Units, Standards and Services Department (MUSSD) was established under the Measurement Units, Standards and Services Act No. 35 of 1995. The department is responsible for, providing accurate and reliable measurement procedures and metrology services, safeguarding the interests of the consumer, maintaining the National Measurement Standards, and updating those standards in conformity with the international measurements system by implementing the laws and regulations of this act.

Each country in the world has a special establishment responsible to realize, establish and maintain the national measurement standards. It is generally called National Measurement Institute (NMI). MUSSD bears the responsibilities of the NMI in Sri Lanka. Establishment, maintenance, and dissemination of national measurement standards in Sri Lanka are done by the National Measurement Laboratory (NML) established under the department. Moreover, various calibration and verification services for measuring instruments used in fields such like industry, engineering, environment, health protection, road safety etc; are provided by MUSSD.

Further the recommendations of OIML (International Organization of Legal Metrology) are utilized in legal metrological activities and pattern approval of electrical and mechanical weighing and measuring instruments, initial and annual verification of such instruments are being done according to those recommendations.

Measurement Units Standards & Services Department laboratory was originally designed and equipped for the purpose of enforcement of the Weights and Measures Ordinance way back in 1937.The laboratory was equipped mainly to verify trader’s measures used in mass, length, volumetric transaction in the imperial system of weights and measures which was the system used in colonial Sri Lanka. The laboratory was entrusted with the custody and maintenance of Sri Lanka National Standards for Mass, Length and Volume primarily for enforcement of the Weights and Measures Ordinance No.37 of 1946 and its subsequence amendments in 1971, 1974 and 1979. As a result of this limited activity, the laboratory remained to be a part of the Weights &Measures Division of the Department of Internal Trade of the Ministry responsible for trade & Commerce for a long period of time.

The Division was upgraded to that of a full Department (Measurement Units Standards & Services Department) in 1997.

In 1974, when Sri Lanka changed its system of measurements from the Imperial System of Units to the International System (Metric System) of units. The Measurement Standards & Services Division of the Department of Internal Trade was given the responsibility of implementation of the Metric conversion program of the country. A Metric Conversion Authority a statutory body chaired by the head of MUSSD was formed and the National Metric Conversion Law, No 17 of 1976 was formulated for these purposes. The Laboratory equipped itself with metric measurement standards during the transition to the metric system during 1970 to 1980 period. These standards remains as Sri Lanka National Primary Measurement Standards.

Sri Lanka is one of the developing nation in the Asia Pacific Region who had the correct vision to establish National Standards of Measurements as early as 1975 by acquiring a copy of a kilogram obtained from International Bureau of Weights & Measures [BIPM] as the National Standards of mass, Zeman stabilized Helium Neon Laser Interferometer to realize the National length standards the meter, a Cesium Atomic Clock to realize the National Time standard the second, Water triple point cell to realize the Thermodynamic Temperature Scale, Standards Lamps for measurement of luminance intensity, Set of Standard Cadmium cell to realize the DC Volt, Set of Calibrated Standards Resistors, Standard equipment to measure Electrical Inductance, Capacitance, Electrical & power etc.

In 1995 the Measurement Units Standards & Services Act No. 35 of 1995 was passed by the parliament. It is the present Measurement Law of the country, which has reaching for consequences, and be of great importance, achieving the optimum required accuracy in all measurements used in trade, industry, science, health, security and environmental protection. The Act encompasses a vast array of fields in metrology and established the Department and the National Measurement Laboratory.

Today the Department has established national standards for mass, length, temperature measurement and to a greater extend standards for electrical, time and frequency measurements. There is an increasing demand from the industry for calibration of photometry and sound measuring equipment. Moreover, there are specialized instrument used by specific industries. This is a vital industrial need and calibrating specialized industrial measuring devices using custom developed techniques would be a major activity of the department.

During this period primary standards for electrical measurements were established by introducing Standards Resisters Voltage Standards, Timer Counter and necessary software to run the above equipment.Providing calibration facilities to leading laboratories in the country is another function carried out by the department.