Is a certified reference material a certified reference material? Before answering this question, it is important to understand the meaning of "certified reference material." A certified reference material is a reference material accompanied by a document issued by an organization providing one or more characteristic values with uncertainty and traceability obtained using an effective procedure. Therefore, a certified reference material is not necessarily a certified reference material.

Certified reference material should have the following basic characteristics:

1. Traceability and uncertainty statement.

2, the preparation, determination and identification of standard substances conform to the effective procedures given by ISO guidelines 34 and 35, and China has equivalent converted the above guidelines into JJF1342 "General Requirements for the development (production) of standard substances" and JJF1343 "General Principles and statistical principles for the determination of standard substances". It has become the technical basis for the review and release of national standard substances.

Only the certified reference material provides a certified value or standard value that can be used for calibration, assigning values to other substances and confirming the accuracy of the measurement, and can be used to claim the metrological traceability of the measurement results.

The above content is the introduction of the certified standard material is the certified standard material, in the daily measurement, other types of standard substances will be used, they are mainly used to carry out measurement quality control, measurement precision confirmation, etc.

Sometimes, in the absence of certified reference materials, these reference materials have to be used to carry out calibration and other activities, but it should be further assessed whether these reference materials meet the characteristics of certified reference materials, or whether the level of traceability and quantitative uncertainty can adequately meet the traceability and accuracy requirements of measurement results.