The following standards shall govern the use of electronic message signs. The nighttime and daytime illumination of an electronic message sign shall conform with the criteria set forth in this section:
A. Illumination Measurement Criteria: The illuminance of an electronic message sign shall be measured with an illuminance meter set to measure foot-candles accurate to at least two (2) decimals. Illuminance shall be measured with the electronic message sign off, and again with the electronic message sign displaying a white image for a full color capable electronic message sign, or a solid message for a single color electronic message sign. All measurements shall be taken perpendicular to the face of the electronic message sign at the distance determined by the total square footage of the electronic message sign as set forth in the "Sign Area Versus Measurement Distance" table in this section:
SIGN AREA VERSUS MEASUREMENT DISTANCE
Area Of Sign (Square Feet) | Measurement Distance (Feet) |
10 | 32 |
50 | 71 |
100 | 100 |
200 | 141 |
Note: For signs with an area in square feet other than those specifically listed in the table, the measurement distance may be calculated with the following formula: The square root of the product of the sign area and 100.
B. Measurement Difference: The difference between the off and solid message measurements using the electronic message sign measurement criteria shall not exceed 0.3 foot-candle at night.
C. Automatic Dimming Technology: Electronic message signs shall come equipped with automatic dimming technology that must automatically adjust the sign's brightness in direct correlation with ambient light conditions not to exceed fifteen percent (15%) of full brightness at night and eighty five percent (85%) of full brightness at day.
D. Minimum Hold Time: The minimum hold time between messages, for an electronic message sign, shall be no less than three (3) seconds. Any such sign with a hold time less than three (3) seconds shall be considered an animated sign and shall be prohibited.
E. Images: Fading, transitioning or dissolving of images shall occur on an electronic message sign of no less than one second, but not to exceed 1.5 seconds, to reduce the abrupt "flashing" effect as the message on the sign changes from one image to another.
F. Color LED: All images on electronic message signs shall be full color RGB LED (light emitting diode). (Note: The RGB color model is an additive color model in which red, green and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the 3 additive primary colors: red, green and blue.)
G. Traveling Messages: Traveling messages are prohibited.
H. Prohibited Hours: Electronic message signs must be turned off between the hours of twelve o'clock (12:00) midnight and six o'clock (6:00) A.M. (Ord. 2012-32, 10-16-2012)