Module 02

Question 1

When color is perceived, it is a result of what four origins?

Answer 1

1. Size of space or object
2. Geometry of space
3. Radiance
4. Background of materials reflecting or transmitting energy of particular regions of the visible spectrum.

Question 2

A light source that emits radiant energy comparatively balanced in all visible wavelengths appears _____ in color.

Answer 2

white

Question 3

What is Correlated Color Temperature? How is it measured?

Answer 3

A measure of the light source’s color appearance defined by the proximity of the light source’s chromaticity coordinates to the blackbody locus.

Measured in Kelvin (K)

Question 4

What is Spectral Power Distribution?

Answer 4

A measurement of the radiant power exitance emitted by the source at each wavelength or band of wavelength over the visible region.

Question 5

What does CRI stand for? Define CRI.

Answer 5

Color Rendering Index.

measures the ability of a light source to accurately render all frequencies of its color spectrum when compared to a perfect reference light of a similar type (color temperature) .

Question 6

What color has shown to be important in the color rendering metrics?

Answer 6

Red (R9)

Question 7

What source of light compliments the appearance of the human face and warm colors the best? Why?

Answer 7

Incandescent and Tungsten Halogen light because they have the highest possible color rendering (CRI 100) similar to sunlight.

Question 8

TM30 is a new way of measuring the color of light. Explain how light is evaluated with TM30.

Answer 8

99 new color evaluation samples (CES) to measure color fidelity (Rf) and Gamut (Rg) area of chromaticity (vividness).

Question 9

Color Rendering is relative. True or False?

Answer 9

True.

Question 10

How is luminous intensity of light measured?

Answer 10

Measured in Candelas (cd) – flux per solid angle in a given direction.

Intensity in a direction(s) can be plotted on a distribution curve or polar graph.

Question 11

What does CBCP stand for?

Answer 11

Center Beam Candlepower

Question 12

What is the measurement of luminous flux or quantity of light emitted by an electrical source?

Answer 12

Measured in lumens (lm) – time rate flow of light. the summation of light from a lamp.

Question 13

Illuminance is measured in _______________ and luminance is
measured in ________________.

Answer 13

foot-candles (fc) or lux (lx)
Candelas per square meter

Question 14

What device is used to measure light intensity at many different angles through a luminaire?

Answer 14

Sphere photometer

Question 15

What is a polar luminous intensity distribution curve? Draw an example.

Answer 15

It is the absolute total light pattern.

Question 16

When calculating the Room Cavity Ratio, the answer is used within a graph to understand the ___________ of ___________.

Answer 16

Coefficient
Utilization

Question 17

What is LLF? Name at least three factors used to calculate LLF. Describe each factor and note whether it is recoverable or non-recoverable.

Answer 17

LIGHT LOSS FACTOR – is a multiplier of several operating and environmental conditions that interfere with the transmission of light, resulting in wasted lumens.

Lumen Dirt Depreciation (LDD) – accumulation of dirt on lamp (recoverable)

Lamp Lumen Depreciation (LLD) – lumen output changes gradually over operating time (recoverable)

Ambient Temperature Factor (ATF) – variations in temperature of environment (non-recoverable)

Question 18

What is the formula for average maintained illuminance in a space?

Answer 18

(total lumens)(CU)(LLF)/area

Question 19

What is the formula for the horizontal illuminance directly below a light fixture?

Answer 19

fc= cp/d^2 (cos 0)

Question 20

What is the formula for vertical illuminance from a light fixture?

Answer 20

cp(sin 0)/d^2

Question 21

When laying out wall washers near a wall, what should be the ratio on center spacing to the setback from the wall?

Answer 21

(one third of the room height arrangement, a=1/3 x h)

3:4.5?

Question 22

What is the ratio of light when grazing a wall?

Answer 22

10:1