Transcript No Slide Title

Fundamentals &
Terminology
LIGHTING TERMINOLOGY &
SPECIFICATIONS
Basic Lamp Types
Incandescent
Fluorescent
Mercury Vapor
Metal Halide
High Pressure Sodium
Low Pressure Sodium
How Lamps Produce Light
Incandescent
HID
Fluorescent
Low Pressure Sodium
Relative Performance of Lamp
Types
Compare:
Relative Light Output
Range of Wattages
Range of Light Output
Efficiency or Efficacy
Range of Rated Life
Relative Light Output
Lamp Type
Incandescent
Mercury Vapor
Fluorescent
Metal Halide
High Pressure Sodium
Low Pressure Sodium
Relative Light
Output
1.0
2.5
4.8
4.8
5.4
7.7
Range of Lamp Wattages
The range of lamp
wattages, and hence
light output, is an
indication of the
scope of applications
of each lamp type.
Low Pressure
Sodium
High Pressure
Sodium
Metal Halide
Mercury Vapor
Fluorescent
Incandescent
0
500
1000
Wattages
1500
Range of Light Output
The range of light
output is also an
indication of the
scope of applications.
Incandescent
Fluorescent
Mercury Vapor
Metal Halide
High Pressure
Sodium
Low Pressure
Sodium
0
50000
100000
Lumens
150000
Lamp Efficacy (1)
The ability of a lamp to convert watts into
lumens is its efficacy
Efficacy is expressed in Lumens Per Watt
One comparison of efficacy is made by
comparing the highest wattage rating of
each lamp type.
Lamp Efficacy (2)
Lamp Type
LPW (Lumens Per Watt)
Incandescent
22.2
Fluorescent
70.7
Mercury Vapor
60.0
Metal Halide
103.3
High Pressure Sodium
140.0
Low Pressure Sodium
183.0
Range of Rated Life
Lo w P r e s s u r e S o d iu m
H ig h P r e s s u r e S o d iu m
M e t a l H a lid e
M e rcy Vap o r
F lu o r e s c e n t
In c a d e s c e n t
0
5000
10000
15000
20000
25000
30000
35000
40000
Range of Rated Life (2)
Fluorescent, mercury vapor and high pressure
sodium lamps have the longest expected life.
Incandescent have the shortest.
Bulbs Types
Fluorescent
Lamps
Incandescent
Lamps
Low Pressure
Sodium Lams
HID
Lamps
Common Lamp & Lighting
Terms
Current (Amp or I):
The flow of electricity
through a lamp or
circuit. It is
measured in
amperes, abbreviated
“A” or “I”
Direct Current: In
direct current, the
flow of electricity is in
a single direction.
Batteries produce DC
current.
Common Lamp & Lighting Terms (2)
Alternating Current:
In alternating current,
the flow of electricity
alternates direction.
The current flowing in
the circuit goes on
and off twice in one
cycle.
The number of cycles
completed in one
second is called the
frequency of the AC
voltage and is
designated by Hertz
(Hz). The most
common frequency is
60 Hz (60 Hertz).
Common Lamp & Lighting Terms (3)
Voltage (V or E): A
measurement of the
electrical force or
pressure. It is
analogous to the
pressure in a water
line. Measured in
volts, abbreviated as
“V” or “E”
Resistance (R): The
resistance to the flow
of electricity.
Measured in ohms,
abbreviated “R.” It is
analogous to the
resistance of water
flow by a sprinkler at
the end of a hose.
Common Lamp & Lighting Terms (4)
Ohm’s Law: The
Watt (W): The power
relationship of voltage
used or consumed by
& resistance. The
a lamp. It is the
current that will flow
product of voltage
in a circuit is
applied to the lamp or
dependent on the
circuit and the current
voltage applied to the
flowing through it,
circuit and the
where the power
resistance in the
factor is unity or 1.0.
circuit. Use I =E/R.
Common Lamp & Lighting Terms (5)
Power Factor: The
ratio of the actual
power being
consumed by the
lamp or circuit to the
apparent power being
consumed.
Power Factor =
Actual/Apparent
The apparent power
is the product of the
voltage and the
current (V x I).
Therefore, the actual
power equals the
apparent power times
the power factor
Actual = V x I x PF
Common Lamp & Lighting Terms
(6)
Kilowatt: A kilowatt
equals 1000 watts.
KW = W/1000
Kilowatt Hour: The
unit of energy.
Energy use is
determined by Energy
= Power x Time.
Utilities charge for
energy used not
power consumed.
Common Lamp & Lighting Terms (7)
Transformer: An AC
device that
transforms the
voltage from the
supply side to the
load side. It can be
designed to raise or
lower the secondary
voltage.
Reactor: A device to
limit the current flow
to a fluorescent, HID
or sodium lamp. It is
sometimes called a
“choke.”
Capacitor: A device
used to correct power
factor.
Light Terms
Lumen: Defines the
total quantity of light
produced by a lamp
regardless of
direction.
Candlepower (CP):
Defines the quantity
of light emitted by a
lamp in one direction,
or the intensity of
light in that direction.
Candlepower
Distribution Curve: A
representation of how
light is distributed by a
fixture or by a reflector
and PAR lamps.
Illumination: The
quantity of light falling
on a surface.
Measured in
footcandles.
Light Terms (2)
Footcandle (FC): The
amount of lumens
falling on an area
with the area
expressed in square
feet.
Lux: The metric
equivalent of the
footcandle with the
area expressed in
square meters.
Lamp Color Terms
The color of a lamp is described by two
independent characteristics:
Color Temperature: The color appearance of
the lighted lamp
Color Rendition: How colors appear when
lighted by the lamp.
Lamp Color Terms (2)
Color Temperature
(Kelvins, K): The
color temperature of
a lamp is based on a
theoretical object
called a black body
which when heated,
emits light.
At a given
temperature, the
black body has a
distinct color
appearance. The
heated temperature is
measured and the
value of that
temperature is
designated its color
temperature.
Lamp Color Terms (3)
Color Rendition: An
evaluation of how
colors appear when
lighted by the lamp.
The color rendering
ability of a lamp is
indicated by its color
rendering index rating
Color Rendering
Index (CRI):
Expresses the relative
ability of a lamp to
match the color
rendering of a
standard illuminant.
A scale of 100 is used
to measure CRI.