Faceplate illumination can be calculated through the
following formula:
Ifp = (Isc Rt)/((4 times f squared)(m+1 quantity
squared))
Ifp = faceplate illumination.
Isc = illumination of scene.
R
= reflectance of scene (75 percent is assumed
and 0.75 used for R; however, the designer may want
to analyze incident and reflected light readings
from the site to determine actual reflectance of the
scenes being viewed at the site).
t
= transmissibility of lens (80 percent is
assumed as an average number and 0.80 used for t.
Specific transmissibility values must be obtained
from the camera/lens manufacturer).
f
= f/number of lens.
m
= magnification from scene to faceplate. (m is
negligible for normal viewing distances, and 0 may
be used for m in all but macro or microscope
applications where the scene is being magnified).
NOTE: The designer shall select operating voltage
and frequency for the installation site.
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The video camera shall conform to EIA 170 and EIA ANSI/EIA-330
specifications. All electronic components and circuits shall be solid
state. Signal-to-noise ratio shall not be less than 46 dB unweighted. The
camera shall exhibit no geometric distortion. The lens mount shall be a C
or CS-mount, and the camera shall have a back focus adjustment. The camera
shall operate from minus 20.0 degrees C to plus 55 degrees C minus 4 to 131
degrees F without auxiliary heating or cooling, and with no change in
picture quality or resolution. The camera shall operate on [60] [50] Hz AC
power, and shall be capable of operating at a voltage of [105 to 130] [205
to 240] [24] Volts.
2.6.1.1
Solid State Image Array
The camera shall have a solid state imager, and the picture produced by the
camera shall be free of blemishes as defined by EIA ANSI/EIA-330. The
camera shall provide not less than 550 lines of horizontal resolution, and
resolution shall not vary over the life of the camera.
2.6.1.2
Sensitivity
Camera shall provide full video output with the infrared cut-off filter
installed, without camera automatic gain, and a scene reflectance of 75
percent using an f/1.2 lens giving a camera faceplate illumination at 2850K
of 1.0 lx (0.1 footcandle).0.1 footcandle.
SECTION 16751A
Page 22
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