The English name of the standard sample has been officially determined as Reference material(referred to as RM) since 1978. The original meaning is a reference object, in fact, the substance provides one or more quantitative values as a reference value for the accuracy of other measured values.

That is to say, a method is used to measure it, and if the measured value is consistent with the "reference value" provided by it, we believe that the measurement method is qualified and reliable.

On the contrary, if it does not match, then we consider the measurement method to be unqualified and not feasible. Therefore, in order to be more consistent with the use of habits, we provide the quantity value of the "standard value", the substance is called the sample that provides the standard value is the standard sample.

The standard sample has two characteristics:

1, with enough uniformity. Please note that it is not very uniform but uniform enough. Because it is only to ensure the consistency of the application effect of technical standards in different space applications, that is, to meet the requirements of the technical indicators in the text standard.

2. It's well established. Please note that this does not mean very accurate but very certain, that is, the standard value is required to be reliable. It is not required to be very accurate, only that it should meet the technical indicators in the text standard.

The above is an introduction to the definition of a standard sample, which is a material identical or similar to the sample to be tested, but with traceable confirmation and a specified standard value of measurement uncertainty. This standard material is mainly used to develop (formulate) various character technical standards, verify the ability of relevant laboratories to use character technical standards, and test the technical validity of character technical standards.