Automated analysis of submicron particles by computer-controlled scanning electron microscopy

Automated analysis of submicron particles by computer-controlled scanning electron microscopy is generally possible. The minimum diameter of the detectable particles is dependent on the mean atomic number of the particles and the operating parameters of the scanning microscope. The main limitation with regard to particle size is set by the quality of the particle detection system, which generally is the backscatter electron detector. The accuracy of the results of the x-ray analyses is very often strongly affected by specimen damage, omnipresent especially for environmental particles even at low electron energies and probe currents. With the exception for light elements, the detection limit is approximately 1 wt%. Device-related limitations to automated analysis may be specimen drift and an unreliable autofocus function.