Thickness determination by measuring electron transmission in the TEM at 200 kV

The dependence of electron microscopic contrast on atomic number has been separated experimentally from that on mass thickness in a Philips CM20 transmission electron microscope at 200 kV. The formula obtained for one-component films has been generalised for multicomponent films. A procedure for specimen thickness determination is proposed in conjunction with composition determination by energy dispersive X-ray spectrometry.