 The electron multiplier or aperture permits only those electrons emanating from a very small area of the electron image, representing a similarly small area of the visual image.The entire image is scanned several times per second to produce an electrical signal suitably representative of a moving visual image.Because the dissector does not store charge, it is useful for viewing the inside of furnaces and monitoring welding systems as it does not suffer from the "flare" normal picture tubes experience when looking at intense lights.