GB/T 20066 Steel and iron.Sampling and preparation of samples for the determination of chemical composition
GB/T 6379.1 Accuracy(trueness and precision)of measurement methods and results Part 1:General principles and definitions
GB/T 6379.2 Accuracy(trueness and precision)of measurement methods and results-Part 2:Basic method for the determination of repeatability and reproducibility of a standard measurement method
GB/T 6682 Water for analytical laboratory use.Specification and test methods