Scanning Electron Microscope and Energy Dispersive Spectrometer
Scanning electron microscope is a useful tool for studying the minute detail surface structure of museum objects by magnifying the image up to 100,000 times. Coupled with various detectors such as the Everhart Thornley detector, back scattered electron detector and energy dispersive spectrometer, the surface structure, chemical distribution as well as the elemental composition of the sample could easily be studied. By controlling the pressure of the vacuum chamber, less conductive materials can be examined by the gaseous detector without complicate sputter coating.
The scanning electron microscopy has widely been used by conservation scientists in studying mineral pigments in cross section, identifying corrosion products, studying metallographic structures and characterizing unknown salts crystallization in historic buildings. The major advantage of scanning electron microscopy over the optical microscopy is the higher magnification and higher depth of field due to the low diffraction of electron beam.