A-A-2084
June 6, 1983
SIGN
(ELECTRICALLY POWERED, EXIT)
The General Services Administration has authorized the use of
this commercial item description.
This description covers the requirements for signs which designate and provide directions to exit locations and shall be of the following, classes, styles, and kinds.
Type 1 – 120 volts
Type 2 – 277 volts
Class A – Single face
Class B – Double face
Style I – Top Mounting
Style II – End Mounting
Style III – Back Mounting
Style IV – Pendant Mounting
Style V – Flush Mounting (Pressure Sensitive)
Kind a – Opaque Letters & Translucent Background
Kind b – Translucent Letters & Background
Salient characteristics:
Dimensions. Unless otherwise specified, the exterior dimensions of the sign shall be in accordance with the manufacturers’ standard practice. The “message face” dimensions shall be as follows (all dimensions are minimum):
Letters – 0.75 inch strokes, 6.0 inches high, 2.50 inches wide (except for the letter “I”)
Spacing between letters – 0.50 inches + 0.125 inches (spacing between letters shall be uniform).
Background margin surrounding the word “EXIT” – 3/4 inch.
Directional Arrows. Shall be selected at time of installation.
Options. The following shall be available as specified:
(1) Color of letters – white, green or red.
(2) Color of background – white, green or red.
Illumination. Sign shall be electrically powered, with a minimum of two electrically independent sources of light.
Electrical Power. Each sign (including double face) shall be rated at no more than 15 watts.
Guaranteed Life. Lamps shall have a life of at least 10 years.
Performance and Testing Requirements:
Reflected luminance (brightness). Sign (deenergized) shall be placed in an environment of uniform incident illumination measuring 5.0 foot-candles. Incident illumination shall be measured and certified with a calibrated cosine-corrected illumination photometer (see Figure 1 for suggested arrangement); following certification of the 5.0 foot-candle incident light, the illumination photometer may be removed. Luminance (brightness) measurements shall be made on the sign faces (letters and background) at the points indicated in Figure 2 “EXIT” (figure). Each point of measurement shall be between 1/4 and 3/8 inch in diameter. The brightness measurements shall be made with a calibrated luminance telephotometer (for measurements made on the colored portions of the sign faces, the luminance telephotometer should be calibrated in the same color region of the spectrum). When tested as specified, the minimum measured light at any point on the signs bright surface shall be no less than 3 foot lamberts; and the maximum measured light at any point on the signs dark surface shall not exceed 2 foot lamberts.
Generated luminance. With all light sources energized at rated voltage, the sign shall be placed in environment with no other sources of light (i.e., zero incident illumination). Luminance (brightness) measurements shall be taken on the sign face (letters and background) at the points indicated in Figure 2. Each point of measurements shall be between 1/4 and 3/8 inch in diameter. The brightness measurements shall be made with a calibrated luminance telephotometer. When tested as specified, the average measured light on the sign’s bright surface shall be between 4.0 and 6.0 foot lamberts. The maximum measured light at any point on the sign’s bright surface shall be no greater than 12.0 foot lamberts. The measured light at any point on the sign’s dark surface shall not exceed 2/3 of the value of the lesser one of the two nearest measured bright points.
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