Positive material identification (PMI) is the analysis of a material, this can be any material but is generally used for the analysis of metallic
alloy
An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have prop ...
to establish composition by reading the quantities by percentage of its constituent
elements. Typical methods for PMI include
X-ray fluorescence
X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by being bombarded with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis ...
(XRF) and
optical emission spectrometry (OES).
PMI is a portable method of analysis and can be used in the field on components.
X-ray fluorescence (XRF) PMI can not detect small elements such as carbon. This means that when undertaking analysis of stainless steels such as grades 304 and 316 the low carbon 'L' variant can not be determined. This however can be analysed with optical emission spectrometry (OES)
References
Elemental analysis
Chemical tests
Quality control
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