| Lighting Term |
Definition |
| A-Lamp |
- The most common general-service, rough-service bulb/lamp (ex: 40W, 60W, 100W). Called A-Lamps because they're shaped like an apple.
- This type of incandescent lamp is generally used in most indoor residential lighting applications. Comes in a variety of colours with clear or frosted being the most common.
- Typically, the higher the wattage, the wider the bulb:
- A19: 19-eighths of an inch = 2-3/8" (60mm)
- A21: 21-eighths of an inch = 2-5/8" (1/4" wider than A19)
- A23: 23-eighths of an inch = 2-7/8" (1/2" wider than A19).
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Amp
(Ampere) |
- Amps (A) is the standard unit for current (I).
- Current is a flow of electrical charge carriers, usually electrons.
- Electric current is either alternating current (AC) or direct current (DC).
- Current = Volts / Resistance (ohms), I = V / R
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| Ballast |
- A transformer that steps down AC line voltage to voltage that can be used by fluorescent or other types of lighting. Used with fluorescent or HID lamps to supply sufficient voltage to start and operate the lamp but then to limit the current during operation.
- Older electro-magnetic ballasts are now being replaced with electronic ballasts.
- Newer electronic ballasts are used with T8 (1") and T5 fluorescent tubes. Electronic ballasts generate 10% more lumens, per watt, verses electro-magnetic ballasts, due to the high frequency semi-conductor circuitry. This also allows them be lighter in weight, quieter, generate less heat (10-30% less energy than electro-magnetic ballasts) and produces less flicker.
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| Base |
- There are different types / sizes of bases for bulbs that screw-in to a socket:
- Candelabra (E12, width=12mm): smaller / thinner base, very common with many Chandelier (torpedo, B10) bulbs.
- Intermediate (E17, width=17mm): this base is common with smaller JDR halogen spot lamps.
- Medium (E26, width=26mm): very common in our residential A-lamp (A19) 40W, 60W, 75W and 100W bulbs.
- Mogul (E39, width=39mm): typically used with HID lamps.
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| Candela |
- Current term used for Candlepower.
- Measure of how much light the bulb produces, measured at the bulb (rather than how much falls upon the target being lit).
- 1 candela = 12.57 lumens
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| Cold Start Lamp |
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Color Rendering Index
(CRI) |
- Measure of a lamp ability to render colors accurately.
- The scale ranges from 1 (low pressure sodium) to 100 (natural outdoor light). A CRI of 85 is considered very good; the closer to 100, the truer the light.
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| Color Temperature |
- Measure (Kelvin) of the colour appearance of a light source which helps describe the apparent "warmth" (reddish) or "coolness" (bluish) of that light source.
- 2700-3000K (27K-30K) = "warm" (WW) or "soft white", 3500 (35K) = neutral, 4000K (40K) = "cool" (CW), 5000K (50K) = full spectrum / daylight.
- Daylight bulbs are not brighter than warm white or cool white bulbs (brightness is measured in lumens), they appear brighter and have a bluer-white light - illuminated objects appear as they would in normal sunlight.
- The color temperature of a lamp has nothing to do with how hot the lamp will get or how much heat will be given off by the lamp.
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Compact Fluorescent Lamp
(CFL) |
- Name used for small fluorescent lamps with various glass tube designs (folded, bridged, spiral).
- Have high color rendering (CRI>80), a longer rated life (2500-12000 hours), produce 55-75 lumens per watt (compared to approx 17 lm / watt for incandescent), and are very energy-efficient.
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| Energy-efficient |
- Reference to lamps / lights that use less energy (power) than regular incandescent bulbs.
- Compact fluorescent and LED bulbs are commonly referred to as energy efficient. Compact fluorescent lamps have a much longer rated life than typical incandescent bulb, with an average rated life of 8000-12000 hours.
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| Filament |
- Tungsten wire that lights-up (incandesces) when an electric current runs through it.
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| Fluorescent Lamp |
- Fluorescent tubes have electrodes at either end, a gas containing argon and mercury vapor, and a phosphor coating on the inside of the glass tubing. Its the phosphor coating that transforms some of the ultraviolet energy created inside the lamp into visible light.
- Fluorescent bulbs produce less heat than incandescent bulbs and are therefore more energy-efficient.
- Fluorescents produce between 50 and 100 lumens per watt, which is 4-6times more efficient than incandescents. That's why a 15-watt fluorescent could be used in place of a 60-watt incandescent.
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| Foot-Candle |
- Amount of light reaching a subject. This is called illuminance. The U.S. unit of measurement of lighting level illumination is the foot-candle (fc). The international unit of measurement of illumination is the LUX (lx), which is an abbreviation for lumens per square metre. 1 fc = 10.76 lux.
- simple example: One foot-candle of light is the amount of light a candle
generates one foot away (how bright the light is one foot away from the source)
- footcandles = lumens per square foot
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| Halogen Lamp |
- Also called tungsten halogen lamp or quartz lamp.
- A type of incandescent lamp that contains a tungsten filament and halogen gases (iodine, chlorine, bromine, and fluorine), which slow the evaporation of the tungsten filament.
- PAR30: Size: 30/8ths of an inch (3.75in) in diameter across the face of the lamp
- MR16: 2.0in (16/8in) diameter across the face of the lamp
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| High Intensity Discharge (HID) |
- Gas discharge light sources - light is emitted when an electric current passes through an gas.
- High Intensity: large amount of light is produced in a relatively small area (arc tube).
- Discharge: light is produced in a gas arc and not by a heated wire.
- Available in mercury vapor, metal halide, high pressure sodium, and low pressure sodium.
- HID lamps have a longer life and provide more light (lumens) per watt than most other light sources. Almost twice as efficient as fluorescents; it would take almost twenty 40 watt 4' fluorescents to match the light from one 400 watt halide bulb.
- 35-to-1000 Watts, up to 24000 hours rated life, 2250-140000 lumens
- All gas discharge lamps require ballasts:
- to provide preheat and ignition voltages
- to provide operating voltage and limit lamp current
- can be solid state electronic (20kHz-60kHz) or magnetic (60Hz)
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High Pressure Sodium
(HPS) |
- Type of High Intensity Discharge (HID) lamp. These energy-efficient bulbs produce a more pleasing light (golden white light / yellowish) and are often used for industrial, security and roadway lighting.
- The arc tube (where light is generated) contains mercury, sodium, and argon gas.
- Last almost twice as long as a Metal Halide bulb and emit more lumens of light for the wattage being used than Metal Halides (approximately 25% more light).
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| Incandescent Lamp |
- Incandescent lamps are our normal bulbs", ones that we use at home. Common incandescent bulbs are 40 watts, 60 watts, 100 watts, etc.
- This type of lamp produces light by heating an element (ex. tungsten filament) to incandescence (+500 C) with an electric current. Producing this heat is very inefficient and wastes electricity.
- These bulbs only produce about 15 lumens per watt.
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| Instant-start Lamp |
- Reference to fluorescent lamps that start instantly without pre-heating the cathodes and without the need for starters.
- A strong voltage is initially applied to the lamp that is many times greater (as high as 940 volts) than its normal operating voltage - basically starting the lamp with brute force.
- Because there is no filament voltage applied by the ballast, instant start lamps are the most energy efficient.
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| LED |
- Light emitting diode. A small electronic device that lights up when electricity is passed through it. LEDs are very energy-efficient and have long rated lives.
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| Lumen |
- The light output of a source; specifically, the amount of light (brightness) that a bulb produces.
- Unit of measurement of light equal to one foot-candle falling on one square foot of area.
- a 60 watt incandescent lamp emits between 450-1000 lumens (lm), or approximately 9-17 lm / watt (@120V or 130V)
- a 50 watt high pressure sodium lamp emits about 3900 lumens (lm), or approximately 78 lm / watt.
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| Metal Halide |
- Type of High Intensity Discharge (HID) lamp.
- Use a starting electrode, which is separated by a thermal shorting switch to eliminate any electrical potential between the main electrode and the starting electrode once the lamp is lit.
- More modern metal halide systems do not use a separate starting electrode, instead the lamp is started using high voltage pulses (Pulse Start Metal Halides).
- Produce light that is high in the blue color spectrum.
- Cost less than High Pressure Sodium bulbs but don't last as long and don't put out as much light.
- "MetalArc" is Osram-Sylvania's trademark for their MH lamps; "Arcstream" and "MultiVapor" are names rademarked by General Electric.
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| MR16 Lamp |
- Halogen metalized reflector lamp that measures 16/8 inches (2") in diameter and directs a sharp, well-defined beam of light. Often used in retail to highlight displays.
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| Ohm |
- Ohms is the standard unit for electrical resistance (R).
- Ohms = Volts / Amps, R = V / I
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| Opaque |
- Term that describes a material that does does NOT transmit visible light.
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| PAR Lamp |
- PAR is an acronym for a parabolic aluminized reflector.
- PAR lamps are excellent flood or spot lights
- May use an incandescent filament, a halogen filament tube, or an HID arc tube.
- PAR lamps (such as PAR20, PAR30, and PAR38) rely on both the internal reflector and prisms in the lens for the control of the light beam.
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| PL Lamp |
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| Rapid-start Lamp |
- A Fluorescent system that does not require starters and takes 1 to 2 seconds to produce light.
- The ballast preheats the electrodes within the fluorescent lamp and initiates the arc without a starter or using high voltage.
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| Rated Life |
- The rated life of a lamp is the time (hours) where 50% of a sample burn out - on average 50% of the lamps will burn out BEFORE the rated life and 50% will burn out AFTER.
- Rated life does not mean all the lamps will last as long as its hourly rating.
- Also, if a lamp has a rated life of 1000 hours and is designed for 130 volts but is used with 120 volts, its "actual life" is considered 2610 hours: Rated life x (rated voltage/operating voltage),to the 12th power
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| Recessed Downlight |
- Light fixture recessed (sunken) into the ceiling that usually focuses light downward. Also called downlight, can, recessed can.
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| Rough Service Lamps |
- This type of incandescent lamp has a tough, shock / vibration resistant filament, which makes it better for trouble lights, garage door openers, etc.
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| Starter |
- Electrical device used in conjunction with a ballast for the purpose of starting an electric discharge lamp like a fluorescent or HID lamp.
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| Task Lighting |
- Lighting specifically installed for an area where a task is performed.
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| Transformer |
- Electrical device that usually transforms 120 volts into 12 volts or possibly 24 volts.
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| Transparent |
- Term describing a material that transmits most, if not all, of the visible light incident upon it.
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| Troffer |
- Large recessed (sunken) light fixture (luminaire) usually installed with the opening flush with the ceiling.
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Vapour-Tight
vapour tight / vapor tight |
- A light fixture or lens that keeps vapor (usually water vapor) or gas from entering.
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| Volt |
- Difference in electrical charge between two points in a circuit. Rate at which energy is drawn from a source that produces a flow of electricity in a circuit.
- Higher the voltage, the higher the current (amps)
- Also called electrical potential, electromotive force, EMF
- Formula: volts = amps x ohms, V = I x R, voltage = electrical current x electrical resistance.
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| Watt |
- Wattage (P) is the amount of electricity used by a bulb/lamp.
- 1 W = power dissipated by 1 amp of current flowing across a resistance of 1 ohm.
- 1 W = power produced by 1 amp of current under an electromotive force of 1 volt.
- One horsepower = 746 watts.
- Formula: watts = volts x amps, P = V x I.
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