A photograph is worth a thousand words and a clear image of an artifact showing exquisite surface detail, is worth a million
The critical aspect to any of investigation is to identify, locate, detect, and analyse any material or features of that material, that will support or disprove a position that the material in question was in any way responsible for a loss and for this, we relay on various types of microscopes.
These microscopes allow our chemists and engineers to very closely examine surfaces and identify the chemistry of the surface and elucidate features which in many cases , tell a history as to how a particular object failed. In the investigation of many matters, the microscope can tell us if the failure event was a gradual event such as a fatigue fracture or a single event such as an overload fracture and in our area of forensic engineering and forensic chemistry, our laboratories use various types of microscopes, which fulfil various specific roles.
First, optical microscopy uses either reflected light microscopes or transmitted light microscopes. The reflected light instruments being used to examine the surface of opaque materials and transmitted light instruments being used to examine primarily thin sections. The digital stereo-zoom microscope features in all our investigations.
These instruments allow for excellent colour information with good depth of field, and allow us to examine fracture surfaces, corrosion processes or products, or overall surface topography. Next to the stereo zoom microscope, the scanning electron microscope (SEM) again features in most investigations.
This instrument works by bombarding the surface of the sample with electrons and sending back information on the which gives information on the composition of a material.
This information is used to construct a digital image, which provides a detailed view of a surface with excellent depth of field, even at a magnification of 10,000x.The SEM is often used in combination with the attached Energy Dispersive X-ray Spectroscopy (EDS) system, which provides additional information on elemental compositions, and is necessary to correctly interpret a SEM microscopy photograph.