XRF PMI TESTING
The XRF principle (x ray fluorescence) is one of the methods for PMI. Equipment used contains low radioactive sources (isotopes) or x-ray tubes. The exposed material reflects the radiation, generating energy. As every element has it's own atomic structure, this reflection will generate a different energy level for every element. This energy is measured and detected, thus identifying the alloy elements. The other method for PMI is Spark emission spectrography. Spectography is based on optical emission. The equipment consists of a probe which releases a spark that is used to vapourise the material being analysed. The atoms and ions in this vapour produce a spectrum which can be optically measured and then recalculated to determine the components of the material. Material properties like structure difference and heat treatments have no influence on the results of the PMI measurements. However, it is important that the surface is identical to rest of the material. Oxides, coatings and dirt on the material will influence the identification results. Also the surface must be smooth. Elements that can be identified using PMI include: Ti, V, Cr, Mn, Co, Fe, Cu, Zn, Ni, Se, Nb, Mo. Interesting to know is that the exposure of radiation is sufficiently low, so that extra safety measures are not required. When dealing with exploitation licenses and preventive maintenance of technical installations, Non Destructive Testing and Examination (NDT / NDE) are indispensable techniques. NDT / NDE offer also the necessary guarantees when quality, expense saving, business security and safety is in order, for both existing and new installations. NDT / NDE decrease the risk of leakage or other defects, which increase the business integrity and safety within the installation and can save expenses.