Understanding Uncertainty Budgets

Internationally agreed methods of evaluating measurement uncertainty are detailed in the Guide to the Expression of Uncertainty in Measurement. The GUM is an essential resource for measurement professionals, and this course is designed to support the use of it.

Becoming familiar with the methods detailed in the GUM can require the assimilation of many abstract concepts simultaneously, which can prove difficult, depending on the prior experience of the learner. In addition, we want to promote genuine understanding of measurement situations, rather than just a ‘calculation recipe’.

This course views measurement uncertainty through the ‘lens’ of uncertainty budgets. This is because they are a fundamental tool used by a wide range of professionals and provide a visual way to understand abstract concepts in uncertainty evaluation. Uncertainty budgets can thus help to improve the accessibility of those concepts to non-statisticians. This course is part of our Measurement Uncertainty learning pathway. We recommend that learners complete ‘Introduction to Measurement Uncertainty’ before enrolling in this course.

This course consists of four modules:

Module 1: Creating a simple uncertainty budget
Module 2: Using a measurement model and finding sensitivity coefficients
Module 3: Non-normal output quantities
Module 4: An introduction to correlation in measurement

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

Learning Outcomes

Understand how the best estimate of a quantity can be found as an average of repeated measured values, with appropriate corrections applied
Calculate the variance and standard deviation of a set of repeated measured values
Calculate the standard uncertainty of a set of repeated measured values
Understand a range of simple probability distributions and when to assign them
Understand how the rows of an uncertainty budget evaluate contributions to the combined standard uncertainty from the individual uncertainty contributions
Calculate expanded uncertainty from an uncertainty budget, assuming a normal distribution
Understand the limitations of the process used, and when to seek advice on using a more complex procedure