The metal found in industrial environments is usually dirty and oxidized. Good surface preparation is key for obtaining the most accurate and repeatable test results on hand-held analyzers. This is especially true with LIBS and the Rigaku KT-100S LIBS analyzer, as LIBS is a surface technique. If your surface is not representative of the metal alloy itself, the condition of the sample surface will impact your results. As with other techniques, like XRF and OES, results will improve with the more sample prep you provide.
All non-representative material, such as paint, coating, corrosion, or scale material, should be removed prior to running an analysis. This can be done by using a third party tool, such as hand files, a dremel grinder, right angle grinder or even a rotary file. This will help ensure that area of the metal you are ablating is actually representative of the metal alloy.
Rather than using your yard’s stationary grinder that be cumbersome and difficult to get to, these hand tools provide a quick, cost effective and easy way to clean the surface area prior to analysis. Cleaning off as little as a square inch can take a few seconds and is that is all that is needed.
The KT-100S handheld LIBS’ on-board Drill Down feature allows the analyzer to remove any left off dust, grinder material, oil, etc. before you collect data. Light Drill Down Mode is recommended for general analysis – even when a sample looks clean. Some samples may require additional service prep, or change in the unit’s Drill Down setting. Examples are plated samples, cast aluminums, magnesium aluminum alloys, bronzes or alloys that have been treated.
Examples of metal in need of surface preparation prior to analysis