Low Vacuum Specimen Chamber Operation

When samples are introduced into a conventional SEM the chamber has to be pumped down to a very low pressure in order that the electron optics can function effectively.

Documents, fabrics or non-conductive samples have to be coated with a thin layer of metal such as gold in order to prevent an excess charge of electrons that would make it impossible to obtain useful images. There are often occasions during forensic examination when it is either undesirable or not possible to coat the sample.

By operating the Specimen Chamber at Low Vacuum documents, greasy samples, antiques, fabrics and even complete articles of clothing can be examined without coating. This preserves the sample in its natural state without the possibility of destroying crucial evidence.

In this mode the SEM can be operated at high kV enabling the X-ray analyser to detect elements over the full energy spectrum.