to prevent them from going below blanking level by less than 5 IRE
units.
e.
CCTV lenses: Provide lenses with automated light level metering
device and an auto-iris. Provide each lens with a metal density
spot filter. Light adjustment by the automatic metering device
shall be a weighted average rather than a simple average or a peak
response. Provide lenses for both 25 and 16.9 mm one and 2/3 inch
format cameras. Provide lenses which are mountable with standard
"C" mounts.
f.
Auxiliary CCTV camera equipment: Equipment shall consist of
camera mounts and housings with environmental protection as
applicable for each camera. Camera mounts shall be heavy duty
industrial type, shall provide stable support for the camera, and
shall be the configuration specified for each individual camera
location. Housing shall protect the camera to ensure continuous
24-hour per day operation under specified environmental
conditions. Housing shall be constructed of a durable material.
Access to housing shall allow for camera and auto-iris removal and
replacement within plus or minus 0.0087 rad 0.5 degree, both
vertical and horizontal centerline alignment. Sealed housings
shall be pressurized with dry nitrogen, or contain two units of
desiccant in the camera body area. Install a 10, 20, and 30
percent humidity level indicator strip in a position that allows
inspection through the enclosure faceplate. Where used,
thermostatically controlled heaters shall be located near the
auto-iris and faceplate and near the midsection of the camera
body. Where ventilation blower is used in housing to prevent high
temperature, it shall be thermostatically controlled. Hinged
louvers shall close over blower exhaust when blower is off. For
exterior cameras, video, sync, tamper, and power cables shall
enter camera housing via weatherproof fittings. Entry into
housing shall not interfere with housing heaters or blower
operation. Provide terminal strips for power inside environmental
housings to distribute 120 volts ac for the camera, heater, and
blower, as applicable. [Provide enclosure sunshade as indicated
for exterior camera location.] [Provide indoor environmental
enclosures which are lockable and dustproof.] [Enclosures shall be
tamper alarmed.]
2.4.17.2
Video Signal
Requirements apply to the video signal present at the video monitor input.
Standard system video level shall be one volt peak-to-peak (Vp-p) composite
video and sync. Standard system impedance shall be 75 ohms over the
be according to SMPTE 170M. Peak-to-peak amplitude of the composite TV
waveform shall be one volt and shall be referred to as standard system
video level. Waveform shall be measured in IRE units on the IRE scale
graticule where 140 IRE units represent one volt. Synchronizing pulse
amplitude of a composite video signal of standard system video level shall
be measured from blanking level to negative peak of the sync pulse and
shall be 40 IRE units, 0.3 volt nominal. Video amplitude of a composite
video signal of standard system video level shall be measured from blanking
level to reference white level and shall be 100 IRE units, 0.7 volt
nominal. Picture setup of a composite video signal of standard system
video level shall be 7.5 IRE units, 7.5 percent of the video amplitude.
Pulse overshoot shall be less than 2 percent of the pulse amplitude. Video
SECTION 13703N
Page 49
Previous Page
