Selection of test/calibration methods

The laboratory shall use appropriate methods and procedures for all tests/calibrations within its scope. These include sampling, handling, transport, storage and preparation of the items to be tested/calibrated.

When the customer does not specify the method to be used, the laboratory shall select methods that have been published in international, regional or national standards, or by reputable technical organizations, or in relevant scientific texts and journals, or as specified by the manufacturer of the equipment.

Although one of the most advantageous features of XRF analysis is its high versatility, a careful selection of a particular method implementation shall be made for each application. One shall be aware that XRF is a phenomenon (not a method in itself), based on which a large and diverse groups of analytical solutions have been implemented. While selecting a particular implementation of XRF, you shall be aware of:

• what type of material needs to be analyzed?
  
  
• which elements need to be determined?
  
  
• what is the expected concentration / weight fraction of the elements in the sample?
  
  
• what is the expected uncertainty for the results?