Determination of the characteristic limits (decision threshold, detection limit and limits of the coverage interval) for measurements of ionizing radiation - Fundamentals and application. Pt. 3: Applications to unfolding methods (ISO 11929-3:2019)

Uncertainties of measurement and characteristic limits such as the detection limit, the limit of detection and the limits of the coverage interval, as well as the best estimate and the standard uncertainty assigned to it are of particular importance in metrology in general and in radiation protection. The quantification of the uncertainty associated with a measurement result provides a basis for the confidence that an individual can place in the measurement result. Conformity with regulatory limits, guidance values or reference values can only be demonstrated by considering and quantifying all sources of uncertainty. Finally, characteristic limits are a basis for decisions under uncertainty. This standard specifically addresses characteristic limits for a non-negative measurand in the measurement of ionizing radiation. However, it can be applied to a wide range of measurement methods that go far beyond the measurement of ionizing radiation. The limits to be defined according to this standard for specified probabilities of wrong decisions allow the assessment of the detection possibilities for a measurand and the physical effect quantified by this measurand as follows: a) the "detection limit" allows a decision to be made as to whether the physical effect quantified by the measurand is present; b) the "detection limit" indicates which smallest true value of the measurand can still be detected by an applicable measuring method. It thus permits a decision as to whether the measurement procedure meets the requirements and is thus suitable for the intended measurement purpose; c) the "coverage interval limits" include a coverage interval that contains the true value of the measurand with a specified probability in the case that the presence of the physical effect is detected. The new edition of DIN ISO 11929 consists of four parts: Part 1: Elementary applications; Part 2: Advanced applications; Part 3: Application of deconvolution techniques; Part 4: Application guide Part 3 deals with the evaluation of measurements using deconvolution techniques, counting multichannel measurements as far as they are evaluated with deconvolution methods, especially alpha and gamma spectrometric measurements. Part 3 also gives instructions on how to deal with correlations and covariances. Responsible is the DKE/GK 851 "Activity measuring instruments for radiation protection" of the DKE German Commission for Electrical, Electronic & Information Technologies in DIN and VDE.