Electronic message centers shall be subject to all applicable restrictions within this chapter, including, but not limited to, area, height and placement, as well as the following conditions:
A. Electronic message sign displays shall be limited to displays, which have gradual movements, including, but not limited to, dissolving, fading, scrolling, or traveling. However, sudden movement is prohibited, including, but not limited to, blinking and flashing.
B. Any permitted signs may be, or may include as an individual component of the total sign area, electronic message signs.
C. Electronic message centers or graphic displays may be changed at periodic intervals prescribed as follows:
1. Such signs shall come equipped with automatic dimming technology which automatically adjusts the sign's brightness based on ambient light conditions.
2. No electronic message sign shall exceed a brightness level of 0.3 foot-candle above ambient light as measured using a foot- candle meter at a preset distance depending on sign area:
Area Of Sign (Square Feet) | Measurement Distance (Feet) |
Area Of Sign (Square Feet) | Measurement Distance (Feet) |
10 | 32 |
15 | 39 |
20 | 45 |
25 | 50 |
30 | 55 |
35 | 59 |
40 | 63 |
45 | 67 |
50 | 71 |
55 | 74 |
60 | 77 |
65 | 81 |
70 | 84 |
75 | 87 |
80 | 89 |
85 | 92 |
90 | 95 |
95 | 97 |
100 | 100 |
3. For signs with an area in square feet other than those specifically listed in the table in this section (i.e., 12 square feet, 400 square feet, etc.) the measurement distance may be calculated with the following formula:
The square root of the product of the sign area and 100
Example: 12 square foot sign: Measurement distance = (12 square feet x 100) = 34.6
4. The brightness measurement shall be performed as follows:
a. At least thirty (30) minutes after sunset or thirty (30) minutes before sunrise, the appropriate city official shall measure and determine the sign's brightness by aiming a foot- candle meter directly at the sign. The measurement will be taken as close as possible to the above prescribed distance from the sign face measured.
b. After the sign brightness has been determined, the appropriate city official shall contact the sign owner or the owner's agent to schedule a time to measure and determine the ambient light conditions with the electronic message center off or while displaying all black copy. The ambient light reading shall be taken with the same foot-candle meter at the same location used to establish the sign's brightness.
c. Once the two (2) light readings have been determined, the second measurement reading shall be subtracted from the first measurement reading. To be in compliance with this standard, the difference of the two (2) readings shall be 0.3 foot-candle or less.
D. Electronic message center signs shall be permitted uses in all nonresidential districts and shall be subject to the following conditions:
1. Such signs shall display static images lasting for a period of one second before transitioning to another static image.
2. Message transitions may contain frame effects as defined, so long as flashing is not utilized.
E. All electronic message center signs in a residential zoning district shall require a conditional use permit.
1. All electronic message centers in residential zoning districts shall not be illuminated between the hours of ten o'clock (10:00) P.M. and six o'clock (6:00) A.M.
2. Such signs shall display static images lasting for a period of three (3) second before transitioning to another static image.
3. Message transitions of such signs shall occur instantaneously and may not utilize animation, frame effects or flashing. (Ord. 2422, 1-21-2013)