ISO DIS 5725-4
Accuracy (trueness and precision) of measurement methods and results - Part 4: Basic methods for the determination of the trueness of a standard measurement method
|Publication Date:||9 January 2019|
|ICS Code (Application of statistical methods):||03.120.30|
|ICS Code (Metrology and measurement in general):||17.020|
This part of ISO 5725
- specifies basic methods for estimating the bias of a measurement method and the laboratory bias when a measurement method is applied.
- provides a practical approach of the basic method for routine use in estimating the bias of measurement methods and laboratory bias;
- provides a brief guidance to all personnel concerned with designing, performing or analysing the results of the measurements for estimating bias.
It is concerned exclusively with measurement methods which yield measurements on a continuous scale and give a single value as the measurement result, although the single value may be the outcome of a calculation from a set of observations.
In order that the measurements are made in the same way, it is important that the measurement method has been standardized. All measurements are to be carried out according to that measurement method.
NOTE In ISO/IEC Guide 99:2007(VIM), "measurement procedure" (2.6) is an analogous term related to the term "measurement method" used in this document.
When a value for the bias of a measurement method is quoted, together with a measurement result obtained by that method, there is an implication that the same property is being measured in exactly the same way.
This part of ISO 5725 can be applied only if an accepted reference value can be established to substitute the true value by using the value, for example,
- of a suitable reference material;
- of a suitable measurement standard;
- referring to a suitable measurement method
- of a suitably prepared known sample.
This part of ISO 5725 considers only those cases where it is sufficient to estimate bias on one property at a time. It is not applicable if the bias in the measurement of one property is affected by the level of a second property (i.e. it does not consider interferences). Comparison of the trueness of two measurement methods is considered in ISO 5725-6.