<Li> <P> Colored SEM image of Tradescantia pollen and stamens </P> </Li> <P> Colored SEM image of Tradescantia pollen and stamens </P> <P> In some configurations more information is gathered per pixel, often by the use of multiple detectors . </P> <P> As a common example, secondary electron and backscattered electron detectors are superimposed and a color is assigned to each of the images captured by each detector, with an end result of a combined color image where colors are related to the density of the components . This method is known as density - dependent color SEM (DDC - SEM). Micrographs produced by DDC - SEM retain topographical information, which is better captured by the secondary electrons detector and combine it to the information about density, obtained by the backscattered electron detector . </P>

Where was the first commercially available scanning electron microscope developed