Metrology is defined as the science of measurement. This science is divided into three categories that namely scientific metrology which deals with the organization, development and maintenance of measurement standards, Industrial metrology that deals with the assurance of the adequate functioning of measurement instruments used in industry, including  production and testing processes, last but not least is Legal Metrology concerned with measurements where these influence the transparency of economic transactions human health and protection of the environment.

The Metrology Department of the NSI serves the functions of both National Metrology Institute and that of a National Legal Metrology Authority with sole impetus of alleviating technical barriers to trade associated with measurements.

The Scientific and Industrial Metrology division responsible for the following:

• Development of the national measurement system;
• Maintenance of Namibia’s National Measurement Standards through comparison in order to ensure the accuracy, traceability and international recognition of national measurement;
• Demonstration of national measurement capabilities and equivalence of measurement standards;
• Publication and maintenance Calibration and Measurement Capabilities(CMCs)
• Dissemination of measurement traceability to industries, regulatory authorities, health and environmental sector in Namibia.