STP482: Instrument Evaluation of Electrostatic Paper

    Reynolds, R. G.
    Quality control managerPersonal member ASTM, Olivetti Corporation of America, Burlington, N.J.

    Pages: 13    Published: Jan 1971


    Abstract

    This paper is a report on research to find a means of analysis of ZNO coated light sensitive paper from small specimens and be able to predict resultant copy. Present instruments can measure and record similar parameters, but predictable results could not be made since the range, level, and cycle of adjustments were not related to machine cycle. When the methods and controls presented are followed, it is possible to predict optimum copy and make estimates on latitude, background, loss of density of copy, as well as other characteristics related to machine conditions. None of the instruments are new nor are any of the parameters measured new. The research was in determining type and range of instruments, methods of operation, and calibration to duplicate machine cycle. It was also necessary to determine and measure all elements of the machine cycle. The first study is of the machine to determine light level and variations due to system and voltage. This includes light on both background and image. Other machine factors are exposure time, dark decay time, charge, time cycle of copy, and any special machine components such as preexposure, double exposure, etc. The combination of instruments then may be set up to duplicate these machine functions. These may include turntable, light source, electrometer, recorder, voltage generator, variac, and programmer to operate and control the instruments over all ranges and in same sequence of machine operation. The third and of equal importance are methods and proof of calibrations. For example, a lightmeter reading on level of light source, even when taken by placing meter in specimen exposure position, is not enough. The calibration must prove that the light level is not an average reading or that there are no high or low points in the specimen exposure plane. The entire system must be automatic and adjustable, equal to full range of machine adjustments. Production of the electrophotographic curves should take no longer than a similar copy in the machine. A test of the system is when you can make a copy on the machine, set the instruments at same levels, and then show in the recording the background, best copy, image loss or any problem or area that requires explanation.

    Keywords:

    dark decay, delta, corona, electrophotographic curves, electrostatic paper, foot candle, foot candle seconds, light dark decay, light decay, probes, evaluation, tests


    Paper ID: STP46068S

    Committee/Subcommittee: F05.06

    DOI: 10.1520/STP46068S


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