Training and consultancy for testing laboratories.

Archive for the ‘Measurement uncertainty’ Category

Estimation of bias between two sampling methods

Cargo steel drums

Measurement uncertainty has two main contributors, namely sampling uncertainty and analytical uncertainty, but most laboratory analysts tend to equate analytical uncertainty as its measurement uncertainty based on the sample received.  This may be true when the target (population) lot sampled is homogeneous where every part of the target have an equal chance of being incorporated in the sample…..

Estimation of bias between 2 sampling methods

 

A worked example to estimate sampling precision & measurement uncertainty

Soil sampling B1

Nearly all analysis requires the taking of a sample, a procedure which itself introduces uncertainty into the final test result.  Hence a measurement uncertainty should cover both the uncertainties of sampling and analysis….

A worked example to estimate sampling precision and MU

Sampling designs for uncertainty estimation

IMG_6894

Experimental sampling designs for uncertainty estimation

Notes on sampling in chemical measurement

IMG_6916

Notes on sampling in chemical measurement

Decision risks in conformance testing – Part IV

DOE.jpeg

Decision risks in conformance testing – Part IV

Decision risks in conformance testing – Part III

3-d-image

Decision risks in conformance testing – Part III

ISO/IEC 17025:2017 & Decision Rule

Lab Picture 3

New ISO 17025 and Decision Rule