Positive material identification (PMI) is a process used to identify and verify the composition of a material. There are two main methods used for PMI: optical emission spectroscopy (OES) and X-ray fluorescence (XRF).
OES is a type of spectroscopy that uses an electric arc to excite a sample and measure the light emitted. This light is then analyzed to determine the elemental composition of the sample. OES is a fast and reliable method for PMI, and is often used for metals and other inorganic materials.
XRF is a type of spectroscopy that uses X-rays to excite a sample and measure the fluorescent radiation emitted. This radiation is then analyzed to determine the elemental composition of the sample. XRF is a fast and reliable method for PMI, and is often used for alloys, plastics, and other organic materials.
Overall, both OES and XRF are reliable methods for PMI, and can be used to accurately identify and verify the composition of a material. These methods are often used in industries such as aerospace, automotive, and medical, where the composition of materials must be known in order to ensure safety and quality.