Lighting Terminology

AC POWER:

In direct current (DC), the electric charge (current) only flows in one direction. Electric charge in alternating current (AC), on the other hand, changes direction periodically.

 

AMPERE (AMPS):

An ampere is a unit of measure of the rate of electron flow or current in an electrical conductor. One ampere of current represents one coulomb of electrical charge moving past a specific point in one second.

 

AVERAGE RATED LIFE:

In the light bulb industry, the Average Rated Life (ARL) is how long it takes for half the light bulbs in a test batch to fail. It's also been called a half-life.

 

BALLAST:

In a fluorescent lighting system, the ballast regulates the current to the lamps and provides sufficient voltage to start the lamps. Without a ballast to limit its current, a fluorescent lamp connected directly to a high voltage power source would rapidly and uncontrollably increase its current draw.

 

CHROMATICITY:

Chromaticity is an objective specification of the quality of a color regardless of its luminance. Chromaticity consists of two independent parameters, often specified as hue (h) and colorfulness (s), where the latter is alternatively called saturation, chroma, intensity, or excitation purity.

 

DC POWER:

In direct current (DC), the electric charge (current) only flows in one direction. Electric charge in alternating current (AC), on the other hand, changes direction periodically.

 

DIODE:

Diodes can be used as rectifiers, signal limiters, voltage regulators, switches, signal modulators, signal mixers, signal demodulates, and oscillators. The fundamental property of a diode is its tendency to conduct electric current in only one direction.

 

DRIVER:

In electronics, a driver is a circuit or component used to control another circuit or component, such as a high-power transistor, liquid crystal display (LCD), and numerous others.

 

DRIVER ON BOARD:

An LED driver rectifies higher voltage, alternating current to low voltage, direct current. LED drivers also protect LED's from voltage or current fluctuations.

 

ELECTROLYTIC CAPACITOR:

An electrolytic capacitor is a polarized capacitor whose anode or positive plate is made of a metal that forms an insulating oxide layer through anodization. This oxide layer acts as the dielectric of the capacitor.

 

FOOTCANDLE (FC):

A foot-candle is a non-SI unit of illuminance or light intensity. The foot-candle is defined as one lumen per square foot.

 

HEAT SINK:

Simply put, a heat sink is an object that disperses heat from another object.

 

ILLUMINANCE:

Illuminance is measured as the amount of light striking a surface.

 

INITIAL LUMENS:

Initial lumens is also known as initial light output. It refers to the total amount of light produced by a particular lighting device just after it has stabilized but before depreciation (loss of operational efficiency) has started.

 

INTEGRATED CIRCUIT:

 An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material.

 

LED:

The major uses of LED (Light Emitting Diodes) is to illuminate objects and even places. Its application is everywhere due to its compact size, low consumption of energy, extended lifetime and flexibility in terms of use in various applications.

 

LED DRIVER:

The LED driver is a self-contained power supply that regulates the AC current power to the low DC voltage LED. They ensure that a constant flow of power is maintained even as the LED's electrical properties change with increased temperature.

 

LENS:

lens is a trans-missive optical device that focuses or disperses a light beam by means of refraction. A lens can focus light to form an image, unlike a prism, which refracts light without focusing.

 

LOW VOLTAGE LIGHTING:

Low voltage lighting systems use a transformer to reduce normal line voltage to 12 or 24 volts. It is often used in recessed, track, pendant, landscape, and display lighting applications.

 

LUMEN DEPRECIATION:

Lumen depreciation is the luminous flux lost over time, and thus the complement of lumen maintenanceLumen maintenance compares the amount of light produced from a light source or from a luminaire when it is brand new to the amount of light output at a specific time in the future.

 

LUMINOUS EFFICACY:

 

Luminous efficacy is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power, measured in lumens per watt in the International System of Units

 

OPTICS:

Optics is the branch of physics that studies the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light.

 

PHOSPHOR:

Phosphor, solid material that emits light, or luminescence, when exposed to radiation such as ultraviolet light or an electron beam.

 

RATED LAMP LIFE:

Just like any light bulb, projector bulbs have an expected operating time, called lamp life. This value is expressed in hours and represents the number of hours before the lamp is at half its original brightness.

 

SOLID STATE LIGHTING (SSL):

Solid-state lighting (SSL) refers to a type of lighting that uses semiconductor light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination rather than electrical filaments, plasma or gas.

 

VOLTAGE (V):

Voltage is what makes electric charges move. It is the 'push' that causes charges to move in a wire or other electrical conductor. Voltage is an electrical potential difference, the difference in electric potential between two places. The unit for electrical potential difference, or voltage, is the volt.

 

WATT (W):

The watt is a unit of power. In the International System of Units it is defined as a derived unit of 1 joule per second, and is used to quantify the rate of energy transfer.

 

LUX:

The unit of illumination in the international system of units (SI). One lux/light is the amount of illumination provided when one lumen is evenly distributed over an area of one square metre.

 

LUMINOUS FLUX:

Luminous Flux is energy per unit time that is radiated from a source over visible wavelengths. Thus, luminous flux is a weighted average of the Radiant Flux in the visible spectrum.

 

LUMENS:

The unit of luminous flux, or amount of light, defined as the amount streaming outward through one steradian (a unit of solid angle, part of the volume of space illuminated by a light source) from a uniform source having an intensity of one burning candle. The lumen is used in calculations regarding artificial lighting.

 

COLOUR RENDERING INDEX:

Also referred to as CRI, this index measures the ability of a light source to reveal colours of objects in contrast to a natural light source, such as the sun filtering in through your windows. It's the measurement of light in relation to how it affects the appearance of colour. This range can also depend on the "temperature" of the light.

 

KELVIN/COLOUR TEMERATURE:

Colour temperature is a way to describe the light appearance provided by a light bulb. It is measured in degrees of Kelvin (K) on a scale from 1,000 to 10,000. Typically, Kelvin temperatures for commercial and residential lighting applications fall somewhere on a scale from 2000K to 6500K. The lower the degree of Kelvin, the warmer the light glows. High degrees of Kelvin will result in a brighter, white light.

 

BEAM ANGLES:

The beam angle of a light fitting is the angle at which the light is distributed or emitted. Lamps such as Halogens and LED’s come in a variety of angles from, 4 degrees to 60 degrees with some of the larger halogen lamps up to 120 degrees.

 

IES FILES:

A file with the IES file extension is an IES Photometric file that stands for Illuminating Engineering Society. They are plain text files that contain data on light for architectural programs that can simulate light. The program using the IES file (Dialux) can interpret it to understand how to display the correct lighting patterns on things like roads and buildings.

 

WATTS:

The watt is a method of measuring the rate of energy transfer of an appliance. A one watt light bulb, for example, will change one joule of electrical energy into light energy (and some heat/sound) every second. It is a measure of an appliance's power.

 

IP RATING:

INGRESS PROTECTION MARK. Giving customers a clear indication of the item’s resistance to various types of unwanted intrusion.

 

First digit - protection from foreign body and particulate ingress:

0

Not rated (or no rating supplied) for protection against ingress of this type.

1

Protection against solid objects larger than 50mm (accidental contact with open palm), but not against deliberate body contact.

2

Protection against solid objects larger than 12mm (accidental contact with a finger).

3

Protection against solid objects larger than 2.5mm (tools and wires).

4

Protection against solid objects larger than 1mm (fine tools and wires, nails, screws, larger insects and other potentially invasive small objects)

5

Partial protection against dust and other particulates, such that any ingress will not damage or impede the satisfactory performance of internal components.

6

Full protection against dust and other particulates, including a vacuum seal, tested against continuous airflow.

 

 

Second digit - protection from moisture ingress:

0

(or X - see section below): Not rated (or no rating supplied) for protection against ingress of this type.

1

Protection against vertically falling droplets, such as condensation, sufficient that no damage or interrupted functioning of components will be incurred when an item is upright.

2

Protection against vertically dripping water when enclosure is tilted up to 15° off vertical.

3

Protection against direct moisture spray at angles up to 60° off vertical.

4

Protection against splashing water from any direction, tested for a minimum of 10 minutes with an oscillating spray (limited ingress permitted with no harmful effects).

5

Protection against low-pressure jets (6.3 mm) of directed water from any angle (limited ingress permitted with no harmful effects).

6

Protection against powerful jets (12.5 mm nozzle) of directed water from any direction.

7

Protection against full immersion for up to 30 minutes at depths between 15 cm and 1 metre (limited ingress permitted with no harmful effects).

8

Protection against extended immersion under higher pressure (i.e. greater depths). Precise parameters of this test will be set and advertised by the manufacturer and may include additional factors such as temperature fluctuations, depending on equipment type.

9K

Protection against high-pressure, high-temperature jet sprays, wash-downs or steam-cleaning procedures.

 

 

CURRENT:

An electric current is the rate of flow of electric charge past a point or region. An electric current is said to exist when there is a net flow of electric charge through a region. In electric circuits this charge is often carried by electrons moving through a wire.

 

VOLTAGE DROP:

The decrease of electrical potential along the path of a current flowing in an electrical circuit.