Can a Handheld LIBS analyzer be used for PMI testing to comply with API RP 578?

Yes. Handheld LIBS technology does comply with API RP 578. LIBS is an Optical Emission Spectrometry (OES) technique that has been used for PMI testing for many years.

Recently, language addressing Laser-Induced Breakdown Spectroscopy (LIBS) was added to the third edition of  API Recommended Practice 578: Guidelines for a Material Verification Program (MVP) for New and Existing Assets.

You can find the language in section 6.7 Spectrometer Technology. See below for the excerpt:


6.7.2 Portable Optical Emission Spectrometry

In optical emission spectrometry (OES), an electric arc, spark, or laser stimulates atoms in the test sample to emit a characteristic spectrum of light for each element in the sample. The combined light spectra from different elements are passed through a light guide to the optical analyzer. In the analyzer, the light is dispersed into its spectral components, and then measured and evaluated against stored calibration curves.

These devices fall into three groups:

3) The third group is known as laser-induced breakdown spectroscopy (LIBS), in which an atomic emission spectroscopy technique uses highly energetic laser pulses. The laser is focused to form plasma, which atomizes and excites samples. Plasma light emissions provide the spectral signature of chemical composition for practically any material.

When calibrated for metal analysis, LIBS can provide both qualitative and quantitative information to determine which elements are present and in what quantity.

Considerable progress has been made during the past few years in LIBS technology. Handheld LIBS metal analyzers are becoming available that can provide fast in situ chemical analysis with appropriate precision and detection limits (Annex A). The significant advantage of LIBS technology is its wide element range. In principle, LIBS can detect all elements, limited by the power of the laser as well as the sensitivity and wavelength range of the spectrograph and detector. The LIBS technology also can provide low-level carbon analysis, which, in principle, enables LIBS to positively identify a wide range of ferrous alloys.