GB/T 29164-2012Guide for utilization of certified reference materials for composition analysis and physical property measurements of coal (English PDF)

3.1 traceable to SI units, with long-term stability of value

Classical, reliable method of valuation, value is traceable to the SI (International System of Units) units, the standard value is largely unaffected by the oxidative deterioration of coal

The effects of long-term stability, typically the amount of standard coal component substances such as nitrogen and total sulfur in coal, coal arsenic, phosphorus, chlorine, fluorine, Coal Ash

Silicon, aluminum, iron, calcium, magnesium, titanium, potassium, sodium, sulfur and phosphorus.

Such characteristics can be used to measure the standard substance calibration or instrument calibration equipment performance evaluation, test methods and validation studies and

Test quality monitoring.

3.2 traceable to SI units, with a certain measure of stability

Value is accurate and reliable, traceable to SI metric units, the standard value of coal susceptible to oxidative deterioration and change, usually only 1 year

Or longer stability, such as content of the coal calorific value and carbon. They generally increases oxidative deterioration of coal decreased, but the rate of change within a year

Does not exceed the value of the standard uncertainty.

Such characteristics can be used to measure the standard material equipment performance evaluation, test methods and validation studies and test quality monitoring.

3.3 traceable to standard test method, with a certain measure of stability

Setting accurate and reliable traceability to recognized international or national standard test method, commonly referred to as conditional value, having (1-2) years of steady

Qualitative (such as volatile coal, coking indicators) or long-term stability (such as ash, etc.).

Such characteristics can be used to measure the standard material equipment performance evaluation, test methods and validation studies and test quality monitoring.

3.4 traceable to international or national standard, with a certain measure of stability

Value is accurate and reliable, value traceable to recognized international or national standard (national standard methods based on international or value), such as coal, […]