M&E is the process by which data are collected and analyzed to provide information to policy-makers and others for use in program planning and project management.
The method is known as GUM, which stands for Guide to the Expression of Uncertainty in Measurement.
The method is used when you have a reference sample of composition similar to what you expect in your unknown (production) sample, and that reference sample has a certified compositional value.
Understanding GUM and adherence to good test and measurement practices are essential to minimize uncertainties and ensure reliable measurement results for every application.
In the context of test and measurement, GUM stands for Guide to the Expression of Uncertainty in Measurement.