Illumination Concepts and
Calculations in Electrical
Engineering
Illumination
Terminology in Illumination
Luminous Flux: The total amount of light emitted by a source,
measured in lumens (lm).
Luminous Efficiency: The ratio of luminous flux to the total power
input, measured in lumens per watt (lm/W).
Luminous Intensity: The amount of luminous flux emitted per unit
solid angle, measured in candelas (cd).
Lumen: The unit of luminous flux, which is the amount of light emitted
by a source of one candela intensity within a solid angle of one
steradian.
Candle Power: The luminous intensity of a light source, measured in
candelas (cd).
Mercury Vapor Lamp
The construction diagram of a Mercury Vapor Lamp is provided, and its
working principle is explained.
Additional Illumination Terms
MSCP, MHCP & MHSCP: These terms refer to the mean spherical
candlepower, mean horizontal candlepower, and mean hemispherical
candlepower, respectively.
Lamp Efficiency: The ratio of the luminous flux emitted by a lamp to
the total power input, measured in lumens per watt (lm/W).
Depreciation Factor: The factor that accounts for the decrease in
illumination over time due to factors such as lamp depreciation and dirt
accumulation.
Coefficient of Utilization: The ratio of the luminous flux received on
the working plane to the total luminous flux emitted by the lamps.
Waste Light Factor: The fraction of the total luminous flux that is not
utilized on the working plane.
Incandescent Bulb
A short note on the Incandescent Bulb is provided.
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