A reference substance is a material or substance for which one or more characteristic values have been well determined and are sufficiently uniform, and a certified reference substance is a reference substance for which a certificate is attached, and one or more of its characteristic values are determined by a traceability procedure established so that they are traceable to an accurate implementation of the unit of measurement used to represent the characteristic value. And each standard value is accompanied by an uncertainty for a given confidence level. So what is the difference between the use of certified reference materials and other reference materials? The following is a small edition of Bolinda to introduce you.

First of all, it should be made clear that only certified or standard values provided by certified reference substances can be used for calibration, assigning values to other substances, and confirming the accuracy of measurements, and that metrological traceability of measurement results can be claimed through their use.

In our daily measurement, we also use other types of standard substances, which 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 traceability and quantitative uncertainty levels can adequately meet the traceability and accuracy requirements of measurement results.

The certificates of certified reference substances sometimes provide some additional reference values or information values, which usually lack clear metrological traceability, lack uncertainty information or incomplete uncertainty assessment, so their main use is to help users understand the matrix composition of the reference material, judge the applicability of the reference material, or to carry out measurement quality control according to the reliability.

The above content is to introduce the difference between the use of certified reference materials and other reference materials. In addition, the storage conditions of reference materials are determined in the stability study, while the use conditions of reference materials, such as temperature, preparation method, drying method, moisture correction method, mixing method, etc., are strictly determined and followed in the reference material setting process. Failure to use and store in accordance with the regulations will lead to the quantity value of the standard material is no longer valid, and the measurement results are biased from the standard value.