Positive Material Identification (PMI)

NVI uses positive material identification for chemical analysis of welding consumables.  These tests often form the basis of materials traceability reports for fabrication clients who have purchased stock material or wish to identify materials in inventory.

X-Ray Fluorescent

When a material is bombarded with high-energy X-rays, each constituent element emits characteristic secondary X-rays.  These secondary emissions can be measured, revealing the percentage of each element present.  The advantage of this technology is that it is portable and quick.  X-ray fluorescence is a convenient system—the equipment can be contained in a handheld gun—but it cannot measure carbon content.  It is, however, an excellent option for alloyed steels.

Optical Emission Spectroscopy

At NVI, this is the technique of choice for analyzing high-carbon steels is optical emission spectroscopy.  This technique can identify every element on the periodic table, but it requires a large, bulky machine. The spectroscope generates an electric arc and computes the composition of a metal by measuring the characteristic light intensity that elements produce when they are heated.

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