Certified standard samples and national environmental standards
Reference Material (RM): A material with one or more specified characteristics that are sufficiently uniform and stable to be determined to meet the intended use for the measurement process.
Certified Reference Material (CRM): A standard sample in which one or more specified characteristic values have been determined using a metrologically valid procedure, accompanied by a certificate providing a statement of the specified characteristic values and their uncertainty and metrological traceability.
Environmental standard samples (Enviro)Nmental Reference Materials (ERM): An environmental sample or material with one or more sufficiently uniform and sufficiently determined characteristic values that has passed a technical review and is accompanied by a certificate of use, mainly used to calibrate and verify environmental monitoring and analysis instruments, evaluate and verify environmental monitoring and analysis methods, or determine the characteristic values of other environmental samples. Standard samples can be purchased on the National Standard Products Network.
National Environmental Standard Sample (Natio)nal Certified EnviroNmental Reference Materials (CERM): An environmental standard sample that has passed the expert technical review organized by the national environmental protection authority, been approved, issued, and authorized by the national standardization authority, and is accompanied by a national standard sample certificate. One or more of its characteristic values are determined by a traceable source program that can accurately reproduce the measurement unit of its characteristic value, and is accompanied by the uncertainty of the specified confidence level.
Note 1: The definitions of standard samples and certified standard samples are translated from the latest ISO technical guide "ISO Guide 35:2006 Reference materials-General and statistical principles for certification"; the definitions of environmental standard samples and national environmental standard samples are quoted from "HJ/T173-2005 Environmental standard sample research and reproduction technical specification".
Note 2: At present, due to the administrative approval system in our country, the term "reference material" is also used, and the English corresponding to the standard sample and the reference material are Reference Material.
