Photomultiplier Tube. A low-noise vacuum device requiring high voltages to accelerate electrons and producing very high gains. Can detect individual photons. One detected photon on the photo-cathode can produce a very short pulse containing millions of photoelectrons. PMTs usually operate between the blue and red regions of the visible spectru... Found on http://www.coseti.org/glossary.htm
Abbreviation for photomechanical transfer, a Kodak trade name for a process used to make positive paper prints of line copy and halftones. Found on http://www.e-printing.co.uk/glossary.htm