BS ISO 16962:2017 pdf download

BS ISO 16962:2017 pdf download.Surface chemical analysis — Analysis of zinc- and/or aluminium-based metallic coatings by glow-discharge optical-emission spectrometry
1 Scope
This document specifies a glow-discharge optical-emission spectrometric method for the determination of the thickness, mass per unit area and chemical composition of metallic surface coatings consisting of zinc- and/or aluminium-based materials. The alloying elements considered are nickel, iron, silicon, lead and antimony. This method is applicable to zinc contents between 0,01 mass % and 100 mass %; aluminium contents between 0,01 mass % and 100 mass %; nickel contents between 0,01 mass % and 20 mass %; iron contents between 0,01 mass % and 20 mass %; silicon contents between 0,01 mass % and 15 mass %; magnesium contents between 0,01 mass% and 20 mass%; lead contents between 0,005 mass % and 2 mass %, antimony contents between 0,005 mass % and 2 mass %. NOTE Due to environmental and health risks, lead and antimony are avoided nowadays, but this document is also applicable to older products including these elements.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical composition
ISO 17925, Zinc and/or aluminium based coatings on steel — Determination of coating mass per unit area and chemical composition — Gravimetry, inductively coupled plasma atomic emission spectrometry and flame atomic absorption spectrometry
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
4 Principle
The analytical method described here involves the following processes:
a) preparation of the sample to be analysed, generally in the form of a flat plate or disc of dimensions
appropriate to the instrument or analytical requirement (round or rectangular samples with a width of more than 5 mm, generally 20 mm to 100 mm, are suitable);
b) cathodic sputtering of the surface coating in a direct current or radio frequency glow-discharge device;
c) excitation of the analyte atoms in the plasma formed in the glow-discharge device;
d) spectrometric measurement of the intensities of characteristic emission spectral lines of the analyte atoms and ions as a function of sputtering time (qualitative depth profile);
e) conversion of the depth profile in units of intensity versus time to mass fraction versus depth by means of calibration functions (quantification). Calibration of the system is achieved by measurements on calibration samples of known chemical composition and measured sputtering rate.