Downloaded from https://www.everyspec.com MIL-STD-1311D 4.13 Definitions for cathode-ray charge storage tubes. 4.13.1 Definitions. a. Blemish. A blemish is a localized imperfection of the storage assembly that produces an abrupt variation in the amplitude of the output signal. b. Contrast ratio. The ratio of two luminances. c. Dark blemish. A blemish that, under specified test conditions, results in output less than that from adjacent storage surface areas. d. Decay time. The time interval during which the stored information decays to a stated fraction of its initial value. e. Destructive reading. Reading that partially or completely erases the information as it is being read. f.
Dynamic blemish. A blemish whose presence is a function of writing or erasing rates. g. Dynamic range, peak-to-peak disturbance level. The number of incremental output signal levels, each equal to the peak-to-peak target disturbance at that signal level, that may be obtained between cutoff and saturation. h. Dynamic range, rms disturbance level. The number of incremental output signal levels, each equal to the rms target disturbance at that signal level, that may be obtained between cutoff and saturation. i. Erasing rate. The time rate of erasing the stored information from one specified level to another. j. Gray scale response.
The measurable number of steps in the gray scale test pattern which are distinguishable under test. k. Light blemish. A blemish which, under specified test conditions, results in output greater than that from adjacent storage surface areas. l. Luminance. The luminous intensity per unit area on the screen. m. Luminance decay uniformity factor (DD WE ). A time ratio under conditions of dynamic writing and erasing. n. Luminance uniformity factor (D WE ) . A ratio of luminance under conditions of dynamic writing and erasing in which the writing signal is unblanking pulse. o. Luminance uniformity factor (SE). A ratio of luminances under static erasing conditions. p.
Luminance uniformity factor (SW). A ratio of luminances under static writing conditions. q. Pulse train gate time. The total time period during which the erase train is applied to the TUT. r. Reading time (buildup limited). The time period over which erased display rises in brightness to a specified percentage of saturation. s. Reading time (contrast limited). The time period required for a specified degradation in contrast ratio between a written and an unwritten area. t. Saturation level. That output level beyond which no further increase in output is produced by further writing. u. Static blemish. A blemish whose presence is not a function of writing or erasing rates. v.
Target disturbance. The type of spurious signal, generated within a tube, which appears as abrupt variations in the amplitude of the output signal. The variations are spatially fixed with reference to the target area. A blemish, a mesh pattern, and moirй present in the output are forms of disturbance. Random noise (e.g., thermal circuit noise) is not a form of disturbance. w. Usable reading time. The time period over which a usable output is obtained during continuous readout. x. Write saturation level. The output level beyond which no further increase in output is produced by further writing. 13