Quantcast Table 4-2 Minimum Exterior Illuminances

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Application
Minimum
Notes
Illuminance, lx
(footcandles) at
Ground Level*
Approach Zone and
20 (2) Limited Use Gates
Illuminance on the pavement and
Response Zone
30 (3) Secondary Gates
sidewalks
40 (4) Primary Gates
Access Control Zone
100 (10) or twice the
In immediate area where
immediate surrounding
identification and inspection occur.
areas, whichever is
Also vert. Illuminance = 25% of
greater
horizontal illuminance should be
provided at the level of the vehicle
driver.
*Ground level is defined as 15cm (6") above ground level
Table 4-2 Minimum Exterior Illuminances (Ref. 2 (pg. 3) and Ref. 8 (pg. 29-17))
indicated in Table 4-2, may be appropriate where practical and desired. However, careful
consideration of the potential adaptation problems and the design of the lighting of
surrounding areas are required for the safety of traffic and security personnel. It may also
be necessary to provide additional task lighting in the ID and inspection areas to support
adequate identification of vehicle occupants and contents. Lighting may also be mounted at
or below pavement level to facilitate under vehicle inspection or associated with under vehicle
inspection systems (see Section 7.2) (8, 29-20).
As discussed in the IESNA Lighting Handbook, the light source spectral power distribution is
important for identification and inspection tasks such as seeing hair, eye, clothing, complexion,
and vehicle colors. The ability to identify colors accurately and confidently is determined by
the light source spectral power distribution and the illuminance level. This capability is
commonly referred to as color rendition and is measured by the color rendition index (CRI).
To ensure appropriate color rendition, any nominally white light source (CRI > 50) will be
used at the illuminances typically encountered at an ECF (8).
When closed circuit television (CCTV) is used as part of the security operations, it is important
to coordinate the lighting and CCTV system (5,11-1). References 5 and 6 provide further
information on designing lighting systems for use with CCTV.
Another important consideration in the design of the site lighting, is the restart or restrike time
for the selected lamps. Restart occurs when a lamp experiences a loss of power and there is
a time delay before backup power restores power to the lamp and the subsequent restrike or
restart of the lamp. The restart capability should be coordinated with the user. As an
example, high intensity discharge (HID) lamps are more energy conserving than incandescent
lamps, however, they require several minutes to warm up and restart after power is
interrupted (5,11-4). This period of time may be unsatisfactory for security operations. The
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