The National Metrology Institute of South Africa

DOES the accuracy of local measurement results really matter?

All of us rely on accurate measurements in every aspect of our daily lives. In fact, the reliability of measurements is so often taken for granted that we usually do not appreciate the significant importance that measurements play in our normal activities. We take medication in accordance with a specified dosage, buy food and fuel according to its weight, pay for water and electricity according to usage, book flights scheduled to depart and arrive on specified times, eat food that is safe for human consumption (quality assured from farm to fork), drive cars assembled from components manufactured to tight specifications in different parts of the world, use cell phones and other electronic equipment which are compatible with international networks, to name only a few applications.

The trade of goods and services around the world is the lifeblood of the global economy. For customers to consider trade to be fair and benefit from it, for component manufacturing to be effective and efficient and for effective health care and the protection of the environment, measurements taken in different parts of the world needs to be accurate, equivalent to each other, and accepted by each other. Important decisions (economic, scientific, environmental, social and medical-) are based on measurement results.

How Does South Africa Provide for the Accuracy of Its Measurement Results?

The National Metrology Institute of South Africa (NMISA) has a very specific role in this context. The Institute is mandated by Measurement Units and Measurement Standards Act, 2006 (Act No. 18 of 2006) and ensures that measurements performed nationally (and regionally) are accurate and internationally acceptable. NMISA is part of the Department of Trade, Industry and Competition’s (dtic), family of the Technical Infrastructure (TI) Institutes, which also include the South African Bureau of Standards (SABS), National Regulator for Compulsory Specification (NRCS) and the South African National Accreditation System (SANAS), that together provides for confidence in local goods and products and allows for successful prosecution in cases of non-compliance. The accuracy of measurement results can be demonstrated by ensuring that these are traceable to the National Measurement Standards (Government Gazette No. 1131, 19 October 2018) realised and maintained by NMISA. Notable Projects Serving the Needs of Industry, Business and Regulatory Bodies:

• Determining Contaminants in Food and Beverages in Support of Food Safety and to Identify “Fake Foods”

Aflatoxins are acutely toxic and strictly regulated in food. Matrix CRMs confirm the method performance of laboratory test methods and gives confidence to the laboratory and its customers that the test results delivered are accurate. NMISA’s offering of reference materials and proficiency testing schemes are now available through its online store.

• Materials Characterisation for Manufacturing:

A recently upgraded, state-of-the-art materials characterisation facility provides measurement traceability for surface analysis, elemental analysis and material characterisation. It is the only facility in the country that offers turnkey XPS, TOFSIMS, SEM and XRD analysis. The laboratory is assisting various local and international manufacturers with measurements for surface and bulk analysis of nanomaterials, metals, semiconductors, coatings, glass, powders/ particles and polymers. NMISA is currently developing dimensional accuracy evaluation and diagnostic methods for quality assurance in additive manufacturing.

• Reliable Measurements for Law Enforcement

NMISA maintains the only facility in South Africa that is accredited to SANS 1793 – Wet Method for the Calibration of Evidential Breath Alcohol Analysers. This capability supports national regulations on air pollution monitoring, occupational health and safety, and law enforcement (specifically the reliability of evidential alcohol analyser tests).

• Cutting-edge Realisation of South Africa National Time (SAST)

NMISA contributes to the calculation of coordinated universal time (UTC) and realises South African Standard Time (local realisation of UTC).

This Institute has upgraded its time realisation capabilities significantly over the past years to improve its accuracy to below 4 ns (a nanosecond is a billionth of a second and 4 ns represents cutting-edge accuracy). NMISA currently supports the South African element of the international Square Kilometre Array (SKA) radio telescope, known as the MeerKAT radio astronomy telescope, operated by the South African Radio Astronomy Observatory (SARAO). High accuracy time synchronisation of signals from different antennas is required to obtain high resolution images.

• Accurate Measurements for Energy Efficient Light Sources (LEDs)

LED lighting has been widely adopted in South Africa because of its efficiency and cost. Culminating from years of research and development of measurement methods, NMISA became the first SANAS accredited LED calibration laboratory in South Africa in 2018. Since then NMISA’s measurement capabilities have been expanded every year in accordance with the need for safe, energy efficient and high-quality performance LED lighting in South Africa and the region. It includes both photometric and electrical parameters.

• Reliable Power Quality Measurements for the National Power Grid

Integration of large amounts of renewable energy into the national power system, relies on reliable measurements for stable operation. On-site measurement of power quality is required to ensure that connection of independent power producers do not cause undue disturbances to the national network. NMISA has just completed the development of reference standards for current and voltage harmonic source measurements, which means that power quality can now be accurately determined in South Africa.

Unlocking the potential of Small and Medium Enterprises (SMEs) and Co-operatives through:

• Virtual Reality based training modules in accurate measurement.

• Training SMEs in accurate measurement and the Quality Infrastructure.

• Providing direct measurement assistance to SMEs with the potential to export.

• Providing for Reliable Doses of Ionising Radiation in Diagnostic Medical Treatment

NMISA provides expertise and measurement traceability for a national project on establishing a National Audit program in diagnostic radiology for South Africa, supported by the International Atomic Energy Agency (IAEA). NMISA’s services provides medical facilities to ensure:

• correct dosage when ionising radiation (x-rays, etc.) are used for diagnostics (x-ray imaging) or treatment (irradiation of cancerous tumours), and

• accurate dosimetry measurement (dosage monitoring) of workers exposed to radiation (miners, hospital x-ray and radiation centres, nuclear power plants, research facilities, etc.).

Contact Details:

Readers are invited to visit our website: www. nmisa.org and online store https://store.nmisa. org/ and to follow NMISA on social media:

LinkedIn: National Metrology Institute of South Africa

Facebook: National Metrology Institute of South Africa

Twitter: NMISouthAfrica

Instagram: nmisouthafrica

YouTube: National Metrology Institute of South Africa NMISA