What Is Positive Material Identification?
Positive Material Identification (PMI) is the in-field or laboratory measurement of the elemental
composition of metallic components to verify that the material conforms to the specified alloy
designation. It is the primary technique for detecting material mix-ups — the inadvertent
substitution of a lower-grade or incorrect alloy material for the specified one — which represents
one of the most serious and insidious material integrity risks in process plant construction and
maintenance.
PMI Technologies We Deploy:
X-Ray Fluorescence (XRF) Portable XRF analysers bombard the material surface with X-rays,
exciting elemental fluorescence that is measured to determine the elemental composition of the
alloy. XRF is the most widely used field PMI technology — non-destructive, fast, and capable of
identifying and quantifying most alloying elements in a matter of seconds. Particularly effective
for stainless steels, nickel alloys, titanium alloys, and other corrosion-resistant alloys (CRAs).
Optical Emission Spectrometry (OES) Portable arc/spark OES analysers use an electrical spark
to excite elemental emission from the material surface, providing quantitative elemental analysis
including carbon content measurement — which XRF cannot reliably quantify. OES is the
preferred method where carbon content verification is required, such as distinguishing between
carbon steel grades or verifying low-carbon and extra-low-carbon stainless steel grades.