Standards Development

Scope

This International Standard gives guidance on automated qualitative analysis using energy-dispersive spectrometry (EDS) fitted to a scanning electron microscope (SEM).

Automated analysis is a process where a scanning electron microscope is optimised for a particular operation and is then left unattended for several hours, during which time specimens are automatically manipulated, and analysed. The analysis is achieved through the use of a backscattered electron detector, sensing areas with the required range of elemental density for the analysis and an energy dispersive X-ray spectrometer recording the composition of these selected areas.

Whilst in general use the stability of the standard SEM may offer the operator a resolution satisfactory for the investigations taking place, moving to examinations lasting many hours often bring additional problems. The three areas generating the major problems are the stabilities of the high voltage, the column, and the detector or detectors being used. The backscattered electron detector is often used to determine sites of interest, capitalising on its ability to recognise differing densities of material within a specimen. However, during an examination of a material, changes in column or detector stability could lead to a failure of the detector to recognise the desired densities. Thus high voltage and column stability, along with the stability of the detector are again of prime importance.

Purpose

To enable laboratories in academia and industry to optimise the time spent on the routine analysis of metal or geological materials.