Measurement Units, Standards and Services Department –

Need for restructuring


by Dr. Janaka Ratnasiri

The Cabinet at its meeting held on 30.04.2019, having considered the functioning of the Measurement Units, Standards and Services (MUSS) Department, decided to have it restructured in order to render its services more effectively and efficiently, and approved the appointment of an Experts Committee (EC) to make a study in that regard and submit the necessary recommendations. Against this backdrop, it might be useful to review the mandate of the MUSS Dept, its present functioning and whether it fulfills the responsibilities assigned to it by the MUSS Act.

Establishment of the MUSS Department

The MUSS Dept was established under the MUSS Act No. 35 of 1995, about 24 years ago. The Act describes the various functions – scientific, industrial and legal - that the Department is required to perform. Some of these functions, particularly the legal ones, were originally performed for the enforcement of the Weights and Measures Ordinance way back from 1937, when the Imperial System of Weights and Measures comprising Pound, Yard, and Gallon etc. were used. With the adoption of the metric system of measurements the world over (except in the USA and a few other countries) Sri Lanka too adopted the metric system in 1974.

The imperial system of measurements was replaced with the metric system over a transition decade from 1970 to 1980. The conversion necessitated adoption of the new Act in 1995, to provide the necessary legal framework for the new system. All units to be used are defined and the approved units listed in the relevant schedules given in the Act. Today in Sri Lanka, all trade transactions involving sale of commodities and acquisition of services are being carried out in the metric system, except in the case of land transactions.

The Department is better known among the public for its legal metrology service rather than its industrial and scientific services. The Department provides a silent but important service to sustain the country’s economy through the maintenance of a reliable measuring system. The country’s economy heavily depends on the export of its produce for which the accuracy of weighing instruments used in the export trade traceable to international standards is a pre-requisite.

Maintenance of National

Primary Standards

A key function of the MUSS Dept is the establishment and maintenance of Sri Lanka’s Primary Standards of Measurements through its National Measurement Laboratory (NML). Currently the Department has established a set of primary standards comprising a stainless steel kilogram calibrated at the International Bureau of Weights & Measures [BIPM] in 1974 as the National Standard for mass (BIPM communication), Zeman stabilized Helium Neon Laser Interferometer to realize the National length standard for a metre, a Cesium Atomic Clock to realize the National Time standard for a second, Water triple-point cell to realize the Thermodynamic Temperature Scale, Standard Lamps for measurement of luminance intensity, Set of Standard Cadmium cells to realize the DC Volt, Set of Calibrated Standard Resistors, Standard equipment to measure Electrical Inductance, Capacitance, Electrical and power etc. (MUSS Dept. website)

Among the objectives of the NML is participation in inter Laboratory Comparisons with regional countries, to update those standards in conformity with the international measurements system, with traceability to international standards and also as provided in the Act. Once a set of calibrated standards is acquired, it is essential to have them recalibrated periodically and this is provided for in the MUSS Act. The EC may find out whether the primary standards in possession with the NML are being recalibrated at an overseas metrology laboratory in compliance with these objectives.

Verification of weights and measures

It is a statutory requirement of the MUSS Act that all measuring devices and instruments used in the trade be certified annually by Department Inspectors or by its agent to ensure their accuracy is maintained. It is an offence if a trader uses any instrument such as a weighing balance not certified for the current period. The Department has been performing this legal function in respect of weights and measures satisfactorily throughout the country. This is demonstrated by the fact that the country depending on an export economy has not received any complaints from importers for underweight of consignments exported from Sri Lanka.

Today, both in the city’s super markets and village grocery stores, traditional balances and weights have been replaced by electronic weighing balances. Being electronic systems, these instruments are vulnerable to malfunctioning more than the traditional weighing systems, due to various internal and external factors. Hence, the verification procedure for them has to be totally different to that practiced for traditional weights and balances. This also applies to electronic fuel dispensing units installed in fuel sheds throughout the country.

The recommended practice is to calibrate an electronic balance daily against a set of standard weights maintained by the shop owner, and restore the reading using internal calibration system if there is any deviation. The set of standard weights needs to be certified by MUSS Dept Inspectors annually as in the traditional cases. It is important that this procedure is enforced both in super markets and in village retail shops. ( The question is whether the shop owners are disciplined enough to follow this procedure, which is in their own interest. When an electronic balance in a shop displays 1.000 kg, the customer must have the assurance that the weight of the commodity purchased is accurate to the nearest gramme.

In-house calibration services provided by utilities

The MUSS Dept, according to the Act, requires every government department or corporation, which uses a measure or measuring instrument for testing or checking any measuring instrument for the purpose of certification or calibration, shall have such measure or measuring instrument calibrated at the laboratory at such intervals as may be specified by a directive published in the Gazette for the purpose.

Sri Lanka’s utility organizations including the Ceylon Electricity Board (CEB), Ceylon Petroleum Corporation (CPC) and the National Water Supply and Drainage Board (NWSDB) charge money from consumers for quantities of electricity, oil and water, respectively, that they have consumed monthly, based on the readings of instruments used for that purpose.

These instruments, once installed at households, are hardly verified for accuracy, unless a complaint is lodged. The organizations providing this service may have in-house systems for calibrating these instruments, but it is obligatory for them to have their reference standard instruments calibrated regularly against standards maintained at MUSS Dept, as required in the Act. The EC may verify whether such calibrations are indeed being carried out.

Public sector organizations providing calibration services

Sri Lanka has two public sector organizations which provide calibration service for industries and other organizations. One is the Industrial Technology Institute (ITI) and the other is the Sri Lanka Standard Institution (SLSI). These organizations provide a calibration service direct to the industries, trade and the public for a fee. According to the ITI website, ITI provides calibration and measurement services to a large number of industries and other organizations in the spheres of thermometry, mass, electrical, pressure, dimension, volumetric and force. All these services conform to international standards, and have received accreditation from the Swedish Board for Accreditation and Conformity Assessment (SWEDAC). Their reference standards are calibrated in overseas laboratories.

The Sri Lanka Standards Institution website describes its metrology laboratory as an ISO 17025 accredited calibration laboratory and fulfils this national obligation by providing an extensive industrial calibration service, covering a wide range of measurements, which are traceable to National / International Standards, established through reference standards, which are calibrated in overseas laboratories.

The EC may look into the reasons why these organizations seek calibration from overseas laboratories undergoing much inconvenience and cost, instead of seeking MUSS Dept services to get their reference standards calibrated.

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