§ 40-681. Measurements.

(1)

Sign spacing. Detached and off-premises sign spacing shall be measured radially as the shortest horizontal distance between any part of one (1) sign and any part of a second sign.

(2)

Setbacks. Setbacks shall be measured radially as the shortest horizontal distance between any part of a sign and any perimeter lot line for the development site on which the sign is located.

(3)

Residential proximity. Residential proximity shall be measured radially as the shortest horizontal distance between any part of a sign and any lot line of a residentially zoned property.

(4)

Sign area calculations. The sign area shall comprise the area within a line including the outer extremities of all letters, figures, characters, and delineations, or within a line including the outer extremities of the framework or background of a sign, whichever line includes the larger area.

a.

Double-faced sign. The area of one (1) face shall be the sign area.

b.

Cylindrical sign. The area of a cylindrical sign shall be one-half (½) of the circumference multiplied by the height of the sign.

c.

Individual characters. The area of a sign made from individually cut out letters or symbols shall be the sum of the area of rectangles and triangles necessary to enclose each character.

d.

Monument signs. The area of a sign shall not include the pedestal the sign is mounted on.

(5)

Sign height. Height of a monument sign shall be measured from a plane extended horizontally from the surface of the existing adjacent sidewalk, or grade if there is no existing sidewalk, to the top of the sign and shall include the pedestal.

(6)

EVM sign lighting. An EVM sign's lighting shall be measured using one (1) of the following methods:

a.

Illuminance measurement using a light meter.

1.

The distance (rounded to the nearest foot) from which the illuminance is to be measured shall be calculated using the following formula:

Where:

x = Measurement distance in feet

L = Allowable luminance of the sign = 323 cd/m

A = Area of the sign in square feet

ΔI = Change in illuminance = 0.3 fc

2.

Based on the measurement distance calculated above, the illuminance shall be measured at a corresponding distance perpendicular to the center of the EVM sign face. See Figure 40.681.1, Measurement point (plan view).

See Figure 40.681.1, Measurement point (plan view)

3.

The light meter's photocell shall be set up at the measurement point at a height of five (5) feet above grade. The photocell shall be oriented to face the EVM sign panel. See Figure 40.682.2, Photocell orientation (elevation view).

See Figure 40.682.2, Photocell orientation (elevation view)

4.

With the EVM sign displaying a solid white message, a measure of the illuminance shall be taken. For displays which utilize one (1) color only, the message shall be the solid color of the display.

5.

With the EVM sign off, a measure of the illuminance shall be taken.

6.

The illuminance of the sign shall be measured as the change in illumination and shall be calculated using the following formula:

ΔI = I _max - I _min

Where:

ΔI = Change in illuminance

I _max = Illuminance measured with the sign on

I _min = Illuminance measured with the sign off

b.

Luminance measurement using a nit gun. An EVM sign's luminance shall be measured as the brightest part of the sign.

1.

The measurement point shall be located at a distance far enough from the EVM sign that individual LEDs (or other light-emitting source) are not distinguishable but close enough such that only the EVM sign panel is visible in the nit gun's eyepiece (LEDs are grouped in threes: one (1) red, one (1) blue, one (1) green. If these are individually distinguishable the measurement point must be located further away).

2.

The nit gun's target area shall be focused on the brightest part of the sign, as determined by the director of inspection and code enforcement or the director's designee, and a measurement shall be taken. See Figure 40.681.3, Target area.

Figure 40.681.3, Target area

(Ord. No. 24364, § L, 11-7-12; Ord. No. 25231 , § 6, 10-5-16)