Laser Spectroscopy for Rapid Profiling of Steel Bridge Coating, Corrosion, and Heavy Metals. Final Report for Highway Innovations Deserving Exploratory Analysis (IDEA) Project 164.

摘要

The research conducted under NCHRP 164 focused on the development of laser scanning technology that could provide direct measurement of the condition of the bridge surface and undercoating and assess the level of corrosion, if any in the underlying steel structure. The concept is based on a laser ablation process where a high powered laser is focused and fired at a layer of coating, ablating a microgram quantity of mass, and inducing a tiny plasma spark. This spark generates an emission of light with a characteristic spectrum. The characteristic of this spectrum depends on the type of coating or condition of the steel. Once the characteristic spectrum is determined for a known coating type or a known level of corrosion, it is possible to match unknown coatings or levels of corrosion to the known spectrum to identify the nature of the unknown sample. The aforementioned technique is a form of pattern matching or fingerprinting.