BS EN 14726:2019 pdf free.Aluminium and aluminium alloys -Determination of the chemical composition of aluminium and aluminium alloys by spark optical emission spectrometry.
7.2 Reference materials and recalibration samples
The certified reference materials, the reference materials (see ISO Guide 30) and the recalibration samples should he listed and documented in a laboratory iwocedure:
— certified reference materials for calibration (see Clause 10)
— blank sample: high-purity aluminium or aluminium alloy prepared from high-purity constituents (e.g. Al Sn30) (see Clause 10)
— binary samples (if required e.g. for line interference correction (see Clause 10))
— control samples for checking the accuracy of the calibration; they shall not he included in the calibration functions (see Clauses 10 and II);
— samples for the control of the spectrometer drift (see Clause 12)
— recalibration samples for drift correction (see Clause 10).8.1 General case
Sampling plays in essential role in the accuracy of’ the analytical results. Sampling allows obtaining lal)oratory samples WhoSe di menSion are suitable for t he I)repatition oF test samples k)r S—OES and whose chemical composition shall represent that of the material to he tested.
Sampling of molten metal shall be carried out according to IN 14361.
Test samples, shall present a defined area which represents their average chemical composition. This area shall be sufficiently homogeneous across the test section. The position and size of’ the representative sample area varies with the sampling conditions, as well as with the type of alloy and the analytes.
NOTI 1 The test result only refers to the effective test area which is the vaporised fraction of’ the sample. For the simultaneous multi-element analysis ofdifferent alloys, a mean analysis zone should be defined.A piece, suitable for use on the spark stand, is mechanically separated (e.g. by sawing) from the part to be analysed (see NOTE]. Such piece shall have a minimum thickness of approximately 1 mm, cut in such  a way that allows the plane surface to be machined or otherwise prepared. Additionally, it should be large enough for a sealing edge to protrude over the opening of the sample table (exception: air stand). When using small samples, care should be taken to ensure that no overheating occurs due to sparking. NOTE
A small piece of any finished or semi-finished product can never truly represent the whole and a sample of this type cannot be used to certify a cast. To check the homogeneity of a sample using spark spectrometry, the piece of metal or ingot can be analysed at various locations (e.g. along the diagonal through the part); special attention should therefore be given to areas susceptible to segregation. BS EN 14726 pdf download.