What is the value of the reference material, what is the value of the characteristics of the referen

Hello landlord: When setting the value of the reference material, it is necessary to determine the influence of the operating conditions on the characteristic value and its uncertainty, that is, to determine the value of the influencing factor, which can be expressed by numerical value or numerical factor.

When setting the value of a reference material, it is necessary to determine the influence of the operating conditions on the characteristic quantity value and its uncertainty, that is, to determine the value of the influencing factor, which can be expressed as a numerical value or a numerical factor. For example, the melting point reference material used in the standard capillary melting point instrument is affected by the heating rate of the capillary melting point and its uncertainty. The melting point and its uncertainty at different heating rates should be given when the value is fixed.

1. The influence function of the characteristic value.

The characteristic quantities of some reference materials may be affected by the environmental conditions in which they are measured. The influence function is a mathematical expression of the relationship between the value of its characteristic quantity and the influence quantity (temperature, humidity, pressure, etc.). The function of influence of reference materials must be determined when setting a value.

2. Statistical processing of fixed value data.

After technically illustrating the generation of suspicious values for a set of independent measurements for each operator and removing them, the suspicious values can be statistically eliminated again using the Grubbs method (Appendix 2 for the Grubbs test cut-offs) or the Dixon method (see Appendix 3 for the Dixon test cut-off table). (For details, please refer to the national reference material network, when the data is scattered or there are many suspicious values, the measurement method, measurement conditions and operation process should be carefully checked.) List the results of each operator measurement:

Raw data, mean, standard deviation, number of measurements.

The mean and standard deviations of the data measured by two (or more) operators were tested for significant differences.

If the test results are found to be no significant differences, two (or more) sets of data can be combined to give the total mean and standard deviation. If there is a significant difference in the test results, the measurement method, measurement conditions, and operation process should be checked, and the measurement should be re-measured.

Since the common international reference materials PDB have long been exhausted, new reference materials need to be introduced. Although several different standards are used today, δ13 is being calculated

C-value, still normalized using the PDB standard (table.

Table Δ13C values of the US National Bureau of Standards (NBS) reference sample (relative to the PDB standard).

Reference Materials. For example: standard reference for quality testing of agricultural products, control for drug quality control, etc.

From the definition, it can be seen that the reference material has three significant characteristics: (1) it has the accuracy, uniformity and stability of the characteristic value; (2) the value is transitive; (3) Measurement standards in physical form.