Positive Material Identification (PMI)
Inclusion of material test reports (MTRs) has been the accepted method over the years; however, it has been proven that mill certifications and heat markings alone can be unreliable. Since MTRs are generated at the mills that provide the raw stock, by the time the material reaches a manufacturers’ facility, it may have been through many handling processes increasing the chances of error in the heat markings, therefore, the MTR may not be always trusted. This is becoming more common in the stainless steel and nickel alloy fabrication industries. So, International Ship Supply have utilized the latest technology using X-Ray Fluorescence (XRF) hand-held alloy analyzers to perform the positive material identification (PMI).
XRF alloy analyzers are portable hand-held devices that can perform a non-destructive test on the material at any time in merely seconds. XRF works by exposing the material to a flux of x-rays. The atoms then absorb the energy and become temporarily excited and they fluoresce, or emit x-rays. The x-rays emitted by the sample’s atoms possess clearly defined energies that are unique to the elements present in the sample. By measuring the intensity and energy, the XRF instrument can provide qualitative and quantitative analysis. In other words, it can identify the elements, measure the concentration of each and display them on the unit. The data can be downloaded from the unit and saved for reference or creating reports.