unless indicated otherwise. Cable shall be designed for the installation
method intended. Exterior cable runs shall be underground.
2.4.17.5
Video Monitors
a.
Except as specified herein, design video monitors to comply with
SMPTE 170M for distribution monitors and:
(1) Video monitors shall be designed for continuous operation and
shall incorporate printed circuit modular construction.
(2) Monitor design shall provide for easy replacement of printed
circuit modules.
(3) Electronic circuits shall use solid-state devices with the
exception of the cathode ray tube (CRT).
(4) Each monitor shall be constructed to provide rigid support
for electrical systems so that unintentional changes in alignment
or microphonic effects will not occur during operation or movement.
(5) Circuit design shall incorporate safety margins of not less
than 25 percent where possible, with respect to power dissipation
ratings, voltage ratings, and current carrying capacity.
(6) Provide monitors with a rectangular picture tube that
nominally measures [228] [300] [380] [432] mm [9] [12] [15] [17]
inches diagonally.
(7) Provide adequate safeguards to protect personnel from
exposure to high voltage during operation or adjustment.
(8) Front panel controls shall include a monitor power switch,
horizontal hold, vertical hold, height, contrast, brightness, and
focus.
(9) Monitors shall have the following minimum essential
requirements:
(a) Resolution: Horizontal resolution of not less than 450 TV
lines, at 171.3 candela per square meter 50 foot lamberts
brightness.
(b) Geometry: No point in the active raster shall deviate from
its correct position by more than 2 percent of raster height.
(c) Gray scale:
Reproduce not less than 10 discernible shades of
gray.
b.
Mounting and identification
(1) Mount the monitor CRT and other devices subject to burnout or
short operating life to facilitate easy replacement.
(2) Label the printed circuit board's function and provide
component numbers or markings.
(3) To maintain a standard quality and reliability, components
shall be conservatively rated.
SECTION 13703N
Page 51
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