Please note this course is only available for private cohorts. Please contact NPL Training if you would like more information on enrolling a cohort.

Accurately measuring the mass of an object is essential in many applications, from administering the optimum dose of a drug to correctly manufacturing materials with the desired properties.

For more than a hundred years we compared the gravitational force on an object with the gravitational force on a reference piece of metal known as a ‘standard weight’. The standard weight was in turn compared with the International Prototype of the Kilogram (IPK). The IPK is held in the International Bureau of Weights and Measures in France, which was the ultimate reference for all mass measurements. However, the value of the IPK may have changed since it was produced in 1884; contamination, cleaning or time may have increased or decreased its mass.

Since the revision of the SI on 20 May 2019, we can now compare the gravitational force on an object with an electromagnetic force using a Kibble balance. This allows the kilogram to be defined in term of a fixed numerical value of the Planck constant, a constant which will not change over time.

The Kilogram and Mass Metrology course is part of the National Physical Laboratory’s (NPL) Fundamentals of Metrology training programme. The programme is comprised of seven standalone modules, each corresponding to one of the seven SI base units. The module is delivered via a series of pre-recorded video lectures and includes a scheduled live group Q&A session with metrology experts from NPL. Please note this course is only available for private cohorts. Please contact NPL Training if you would like more information on enrolling a cohort.

This course includes the following topics:

• History of mass metrology culminating in the 1889 definition of the kilogram.
• The redefinition of the kilogram, focussing on NPL’s world-leading theoretical and experimental work on the watt and how the kilogram redefinition will improve future mass metrology.
• Exploration of NPL’s fundamental and applied metrology capabilities in the technical areas of mass, density, force, and pressure measurement.

Learners who successfully complete the course will receive an NPL Certificate of Completion.

Module Prerequisites
To lay the foundations for this module, all learners are provided with access to two half-day NPL e-learning courses: Introduction to Measurement and Metrology and Introduction to Measurement Uncertainty. Learners should complete both of these courses before starting this module.