When it comes to the world of lighting its very easy to get confused by all the 100's of terms. This page clearly details each and every one of them!
2GX13 is the technical term used to describe the connection pins on a T5 circular fluorescent light bulb. These light bulbs are available in 22w (225mm), 40w (300mm), 55w (300mm) and 60 watt (380mm) versions.
830 can be used to describe the colour of light produced by a light bulb or fluorescent tube. Colour 830 is primarily found in halogen light bulbs and appears slightly whiter than incandescent light bulbs.
Colour 835 is the standard colour of fluorescent tubes and compact fluorescent light bulbs. Lamps with this colour code are also referred to as having a "White" colour temperature of 3500k.
Colour 840 is also referred to as "cool white", emitting a 4000k colour temperature. Lamps & tubes that produce this colour enhance blues, flatten reds and give a bluish tint to whites & greens.
Colour 845 is also referred to as "cool white". Lamps & tubes that produce this colour enhance blues, flatten reds and give a bluish tint to whites & greens.
865 is more commonly known by the term "daylight". Daylight light bulbs reproduce the colour of the sun on a sunny day. These light bulbs have a colour temperature of 6500 Kelvin.
ANSI is an acronym for American National Standards Institute. These light bulbs are designated by a 3 letter code such as DAF, DED, DDS and DTY. The unique codes are used to match existing lamps to the exact same wattage, shape and beam angle.
ANSI bulbs are for specialist use and have been designed to meet a strict specification.
AR111 light bulbs are a 111mm diameter spotlight light bulb. This type of bulb is generally used for accent lighting so can be purchased in spot, flood and wide flood versions depending on application.
These light bulbs are also available in dimmable and non-dimmable LED versions.
Arc lamps were the first widely used light bulbs and the only type of light available from 1800-1901. The benefits of carbon arc lamps were the super bright output and the fact they were cheaper to light streets than gas or oil.
Today arc lamps can on be found in xenon short-arc forms.
Architectural light bulbs are unusual incandescent linear lamps that aren't to be confused with fluorescent tubes. These light bulbs are also known as Osram Linestra, Radium Ralina, Philips Philinea and Sylvania Linolite.
Please Note: Traditional architectural light bulbs are slowly being phased out in favour of LED Architecturals.
Ba15d is the technical term for Small Bayonet or SBC capped light bulbs. This base is 15mm in diameter and has two pins which twist and lock into the lamp holder. The "d" at the end of the code refers to the double contact on the bottom of the lamp.
Ba22d is the technical term for Bayonet or BC capped light bulbs. This base is 22mm in diameter and has two pins which twist and lock into the lamp holder. The "d" at the end of the code refers to the double contact on the bottom of the lamp.
Bayonet is a style of light bulb cap/base, this base is locked in place by pushing down and turning clockwise. Bayonet light bulbs have two pins, double contact base and can mainly be found in the UK.
Beam Angle refers to the spread of light that comes from a spotlight style light bulb. The most popular beam angle is 36 degree (medium beam angle suitable for most purposes). Also available in spot (12-13 degree) and flood (60 degree).
We offer various beam angles in GU10, MR16 and PAR light bulb styles.
Blacklight Blue (BLB) is a type of UV light that has a filter to block most visible light, the remaining light enhances whites. These light bulbs and tubes can be used for many applications including oil painting/bank note authentication and dramatic lighting effects.
Brightness is the term used to describe the effect of luminance on an observer. The maximum brightness is said to be found in Pure White whilst the minimum is expected to be found in Pure Black.
Candela, sometimes written as cd, is a unit used to measure luminous intensity in a given direction. The term candela stemmed from wax candles of a certain dimension, which were stated to produce one candela in every direction.
Carbon Filament light bulbs are replicas of the original style 1900's lightbulb. These light bulbs are made by dipping silk in a liquid carbon mix which is then wrapped around a mandrel. These light bulbs create a warm cosy light that is popular in restaurants across the UK.
A type of metal halide light bulb that uses a ceramic material for the arc tube instead of glass. This style of light bulb results in better colour rendering and brighter light.
COB is a form of lighting technology that can be found in LED light bulbs. COB is an acronym for Chip On Board and is the most up to date LED technology. Typically this style of lamp is manufactured from 9 or more diodes.
Here at BLT Direct we stock a wide range of COB LED light bulbs which includes LED GU10 and LED MR16 light bulbs.
CRI, sometimes written as Ra, is used to compare a light bulb/light fittings' ability to replicate the sun. An example of this would be a light bulb with a CRI rating of 80, this would mean that the light bulb is replicating 80% of the visible colour spectrum of the sun.
A further example of CRI would be if a light bulb had a 100 CRI rating. This would mean the light bulb would exactly replicate the colours of the sun on a bright day.
Colour temperature, sometimes refered to as CCT (correlated colour temperature), is simply a method of describing the colour characteristics of a light bulb. Colour temperatures range from low (warm/yellowish) type colours all the way up to high (white/bluish) light.
Colour temperature is measured in "Kelvin" which is explained in more detail below. More information can be found on our colour temperatures example page.
Control Gear is a term relating to a piece of electrical equipment that limits/stabilizes current in an electrical circuit. This operation is used for reducing flickering, noise and energy consumption when running fluorescent tubes and compact fluorescent light bulbs.
The most popular items of control gear are high frequency ballasts. Also available are switch start chokes, digital ballasts and ignitors.
Crompton Lamps LTD were founded in 1878 which makes them one of the oldest lamp businesses in the world. Today Crompton are still a UK based company that offer a large range of light bulbs which include LED Light Bulbs and LED Tubes.
Daylight light bulbs are designed reproduce the colour of natural daylight. These light bulbs have a colour temperature of 6000-6500 Kelvin.
Dichroic is a term that describes a reflector that projects most of the heat through the back of the lamp. This means that a 'cool beam' light is emitted, protecting what is being illuminated from damage. A common example of dichroic light bulbs are Halogen MR16 Lamps.
As the heat is dissipated backwards it is not recommended to use a dichroic lamp in an enclosed or recessed fitting.
A dimmer switch is used to control the brightness of light by changing the voltage waveform applied to the lamp, originally for halogen and incandescent lamps but recently also includes CFLs and LEDs. When selecting a dimmer for LED and CFL lamps it is important to consider the total wattage of the lamps to be controlled and select a dimmer switch that that has a lower limit of less than the total wattage of the lamps.
E12, or Candelabra Edison Screw (CES) is a type of screw in lamp base with a 12mm diameter. Light Bulbs of this type are normally found in chandeliers and night lights.
E5, or Lilliput Edison Screw (LES), is a type of screw in lamp base with a 5mm diameter. E5 capped light bulbs are usually miniature style lamps.
Edison Screw is the term describing the screw in base developed by Thomas Edison in 1909. There are now a wide variety of different edison screw caps; E5 (LES), E10 (MES), E12 (CES), E14 (SES), E27 (ES) and E40 (GES) to name a few. The most common type of Edison Screw base is E27, which measures 27mm in diameter.
The original type of ballast, the electromagnetic ballast was introduced with the first iteration of fluorescent lamps.
An electronic transformer is used to reduce mains voltage to a suitable voltage for halogen light bulbs (Not to be confused with LED Drivers). When selecting a transformer it is important to ensure the max wattage is not exceeded by the total wattage consumed by the light bulbs.
Please Note: It is not recommended to "max" out transformers.
IE 5no. lamps x 10 watts each = 50 watts therefore a 60 watt (60VA) transformer would be acceptable, however if you had 6 lamps a 60 watt transformer would be "maxed" out. In this case we would then recommend a 105 watt (105VA) model.
Festoon Lamps are a type of double ended miniature incandescent bulb commonly used in Automotive lighting applications.
Fire Rated Downlights maintain the protection a ceiling gives from fire and prevents smoke and/or flames from passing through. Therefore to comply with building regulations fire rated downlights are required on the ground floor.
Fire Rated Downlights are available in 30, 60 and 90 minute versions.
G10q is a type of 4 pin lamp base that is commonly found on T9 Circular Fluorescent Tubes. The G10q base is usually located on the inside of the tube and has square positioning.
G24d-1 is the type of base found on 10 or 13 watt PLC Compact Fluorescent, Sylvania Lynx-D, Osram Dulux D and GE Biax D Lamps with 2 pins and 2 dowels in left to right alignment. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
G24Q-1 is the type of base found on 10 or 13 watt PLC Compact Fluorescent, Sylvania Lynx-DE, Osram Dulux D/E and GE Biax D/E Lamps with 4 pins and 2 dowels in middle alignment. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
G24Q-2 is the type of base found on 18 watt PLC Compact Fluorescent, Sylvania Lynx-DE, Osram Dulux D/E and GE Biax D/E Lamps with 4 pins and 2 dowels in left to right alignment. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
G24Q-3 is the type of base found on 26 watt PLC Compact Fluorescent, Sylvania Lynx-DE, Osram Dulux D/E and GE Biax D/E Lamps with 4 pins and 2 dowels in right to left alignment. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
Gang is a term used to describe the number light switches or sockets grouped together on one face plate. For example a 2 gang socket will be able to take 2 plugs and a 2 gang light switch will have 2 rocker/rotary switches.
A Germicidal Lamp is a specialist lamp that produces a short wave ultraviolet light that destroys bacteria. These can be used to produce ozone for water filtering and in air conditioning units.
Glare is a term used to describe the visual impairment caused by excessive brightness. Glare can be divided into discomfort glare and disability glare. Discomfort Glare is when a light source in the field of view causes an instinctive need to look away due to overall illumination being too bright. Disability glare is where a light source outside of the field of view causes reduced visibility inside the field of view.
GR10q is a type of 4 pinned lamp base found on 2D compact fluorescent lamps of 10, 16, 21, 28 and 38 watt ratings. The GR10q base is distinguishable by the 10mm gap between the square positioned pins.
GR8 is a type of 2 pinned lamp base found on 2D compact fluorescent lamps of 16, 18 and 28 watt ratings. The GR8 base is distinguishable by the 8mm gap between the pins.
The GU4/GZ4 base is found on MR8 and MR11 Light Bulbs with 2 pins each 4mm apart. The difference between the GU4 and GZ4 bases is that on the former there will be a distinguishable channel on one or both sides of the base, making a GZ4 capped lamp impossible for use in a GU4 lamp holder and a GU4 capped lamp suitable for both types of lamp holder.
GX24D-2 is the type of base found on 18 watt PLT Compact Fluorescent, Sylvania Lynx T, Osram Dulux T and GE Biax T Lamps with 2 pins and 2 dowels in a left to right alignment. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
GX24D-3 is the type of base found on 26 watt PLT Compact Fluorescent, Sylvania Lynx T, Osram Dulux T and GE Biax T Lamps with 2 pins and 2 dowels in a right to left alignment. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
GX24Q-2 is the type of base found on 18 watt PLT Compact Fluorescent, Sylvania Lynx TE, Osram Dulux T/E and GE Biax T/E Lamps with 4 pins and 2 dowels in left to right alignment. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
GX24Q-3 is the type of base found on 26 watt PLT Compact Fluorescent, Sylvania Lynx TE, Osram Dulux T/E and GE Biax T/E Lamps with 4 pins and 2 dowels in right to left alignment. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
GX24Q-4 is the type of base found on 32 or 42 watt PLT Compact Fluorescent, Sylvania Lynx TE, Osram Dulux T/E and GE Biax T/E Lamps with 4 pins and 4 dowels in a square arrangement. For more exact information on dowel positioning please refer to our FAQ page on Compact Fluorescent Plastic Lug Orientation.
GU5.3 and GX5.3 caps are types of lamp base with two pins 5.3mm apart. Commonly found on MR16 Light Bulbs, these bases differ due to the GU5.3 cap having an indent on either side of the base. This indent means that only GU5.3 capped lamps can be used in GU5.3 lamp holders.
A GZ10 base is a variation of the GU10 base that has squared edges rather than rounded. As a result of having a squared base, a GZ10 Lamp cannot be used in a GU10 fitting whereas the latter can be used in either.
GZ10 lamps are usually dichroic, meaning most of the heat emitted from the lamp is projected backwards into the fitting.
Sodium light bulbs are part of the high intensity discharge family. These lamps produce light by passing an electrical discharge through a tube containing sodium vapour.
Sodium light bulbs run at high pressures and temperatures.
Incandescence is a term used to describe visible light emission as a result of high temperatures. Incandescence can be witnessed in the operation of Incandescent Light Bulbs, in which the filament glows red hot to emit light.
Infrared lamps give off infrared radiation outside the wavelength of visible light, however the heat given off is still felt. These lamps can be used for Zone Heating, Catering, Animal Husbandry, Industrial Processing and Medical applications. One of the applications for these light bulbs is outdoor patio heaters.
Infrared lamps are available in Clear, Ruby and Gold glass finishes. Please note the finish of an infrared light bulb is purely cosmetic.
Instant Start is the term used to describe the instantaneous ignition of a light bulb. The term can be used in reference to Control Gear and LED Light Bulbs.
The IP, or Ingress Protection rating of a lighting product describes how well protected it is against dust, accidental contact and water. This is usually displayed as the letters IP followed by 2 digits, the first (ranging from 0-6) denoting the contact and dust protection, and the second (ranging from 0-8) describing the water protection.
IP20 is an Ingress Protection rating that provides low intrusion protection dust and no moisture protection. The first digit explains intrusion protection (2=against fingers or similar sized objects) and the second digit explains moisture protection (0=no protection).
IP44 is an Ingress Protection rating that provides good intrusion and moisture protection. The first digit explains intrusion protection (4=protection against small tools) and the second digit explains moisture protection (4=protected against water spray in all direction).
IP65 is an Ingress Protection rating that provides complete protection against dust and has great protection against moisture. The first digit explains intrusion protection (6=completely dust tight) and the second digit explains moisture protection (5=low pressure water jet protection in all directions).
IP68 is an Ingress Protection rating that provides complete protection against dust and moisture. The first digit explains intrusion protection (6=completely dust tight) and the second digit explains moisture protection (8=protected against prolonged effects of immersion under pressure).
Kelvin is a term used to describe the colour temperature, often displayed as just the letter K. Some common colour temperatures are 2700K, 3000K and 6500K, which relate to Very Warm White, Warm White and Daylight Light Bulbs.
Kilowatt is simply the measure of 1000 watts. When working out savings on our LED and Energy Saving products we refer to kWh which is the typical billing unit used by utility companies in the UK.
An example of kWh would be if a 50w lamp operated for 20 hours (50w x 20 hours) it would consume 1000 watts, this would equate to one kilowatt-hour.
Kosnic Lighting Ltd is a leading brand established in 2002 that produces energy saving and LED lighting products. Their popular range now includes over 700 different lighting products.
An LED Driver is designed to regulate the power to LED light bulbs. The difference between an LED Driver and conventional power supplies is that the LED Driver is continuously responds to the changing needs of the LED.
Lumen Maintenance is the term used to describe the time a lamp takes to depreciate to a certain percentage of the total lumen output. For example if a light bulb has a L80 rating of 15,000 hours, after the 15,000 hours mark the lamp will have reached 80% of its' total lumens.
Replacing wattage as the standard unit of brightness, Lumens is a new measure introduced with the arrival of energy saving and LED Light Bulbs. This was due to these types of bulbs being able to emit the same amount of light as conventional equivalents, with a greatly reduced power consumption.
A luminaire is simply a complete electronic light fitting. Luminaires are hollow fittings that take light bulbs or fluorescent tubes. Some luminaries can be configured with reflectors (directional light) or outer shells (anti corrosive for protection from the elements).
Luminaires are not to be confused with more portable light fittings like table/desk lamps.
Unlike in fluorescence, luminescence describes the emission of light from a substance that is relatively cool. In Lighting Luminescence is caused electrical energy or chemical reactions. An example of luminescence can be found in LED Light Bulbs, which are often described as cool running.
Lux is simply a unit of illuminance. The higher the lux level the more lumens per square meter.
A term used in relation to emergency lighting, maintained describes an emergency luminaire that is continuously lit, even in the event of power loss.
A UK based manufacturer founded in 1994, Megaman have quickly established themselves as a leading brand in the lighting industry. Their success started when they manufactured the world's first CFL GU10 Lamp in 2002.
Mercury light bulbs are a type of discharge lamp, this type of light bulb works by producing radiation from excited mercury vapor. The majority of Mercury lamps give off a white light but they are also available in blacklight blue versions.
Metal Halide bulbs are a hybrid of Mercury and Sodium light bulbs. These light bulbs may also contain halides of metals including scandium, indium and dysprosium.
Monopin is a term used is reference to fluorescent tubes. As its' name states, the monopin fluorescent tubes have only one pin at each end. Designed for specialist applications, monopin tubes are normally only used in explosion proof fixtures.
MR11 describes a type of Multifaceted Reflector that is 11 eighths of an inch in diameter, or 35mm. MR11 light bulbs are commonly found in low voltage decorative and spotlighting applications.
MR8 describes a type of Multifaceted Reflector that is 8 eighths of an inch in diameter, or 25mm. MR8 light bulbs are commonly found in low voltage decorative and spotlighting applications.
A term used in relation to emergency lighting, non-maintained describes an emergency luminaire that only reacts and turns on in the event of power loss.
Northlight is a term used to describe full spectrum fluorescent tubes. These tubes are designed to offer almost perfect colour rendering of over 90Ra, replicating the look of daylight. Applications for northlight tubes vary from specialist design to retail display lighting.
Some lamps are position orientated and have been designed to operate at a certain position. As a result their ratings for these types of lamps have been based on operation in this position.
Burning position orientated lamps in a position different than intended can seriously hamper lamp life, lumen output and colour.
A PAR lamp, or parabolic aluminized reflector lamp, is a type of reflector lamp found in indoor environments and outdoor in weatherproof fittings. PAR Lamps are distinguished by their diameter, for example a PAR16 lamp is 16 eighths of an inch in diameter, or 50mm. The approximate diameter in mm can also be found by multiplying the PAR number by 3.175, for example a PAR38 is 120mm in diameter (38x3.175=120).
A Pendant Light is a common type of single light fitting that hangs down from the ceiling. Pendant lights usually hang on a chain, rod or cord and are designed to bring light from the ceiling closer to where it is needed the most.
The letters' PL stand for Philips Lighting, and are commonly used in association with the letters; T, C, L or S to describe their range of compact fluorescent lamps. PL-L usually stands for Long Single Turn, PL-C (or sometimes D) stands for Compact Double Turn, PL-S stands for Single Turn and PL-T stands for Triple Turn.
Phosphor is a term generally used to describe a substance that emits light when exposed to radiation such as ultraviolet, through a process called luminescence. Phosphor layers provide most of the light emitted from fluorescent tubes and CFL's, and phosphor is often used as a coat for stabilising the output of metal halide lamps.
Photocell is a term used to describe a sensor which detects light. In lighting a photocell sensor is sometimes referred to as a day and night sensor. The photocell sensor detects when light falls below a certain level to activate, and automatically turns off when light has risen back above a certain level.
PIR, or Passive Infrared, refers to a sensor designed to detect movement. A PIR sensor functions by measuring infrared radiation in its' field of view and detecting when something breaks into this view.
Passive is used to describe the sensor as it does not emit an infrared beam, merely detects infrared given off by sources.
A type of metal halide light bulb that uses a quartz material for the arc tube instead of ceramic. This style of light bulb uses reliable, tried and tested technology and is available in a wide range of wattages.
R7s and RX7s are two types of double ended lamp base. The R7s base is commonly found on Halogen Linear Light Bulbs whereas the RX7s is normally found on Metal Halide Lamps.
An initialism for Surface Mounted Diode, SMD refers to mounted LED chips on PCB (Printed Circuit Board). Surface Mounted LED's were one of the first iterations of LED Light Bulbs.
A starter is used in the operation of fluorescent tubes. The starter is designed to preheat the electrodes in a fluorescent tube and produce an ignition pulse to light it up. While the tube is lit, a starter consumes almost no power and will be ready to function again as soon as the tubes have been turned off.
A T12 Tube is a type of fluorescent tube commonly found lighting larger areas such as offices and retail spaces. The T12 Tube was one of the first fluorescent tubes to be manufactured, however is now being phased out in favour of the more efficient T8 Tube which has the same G13 base. T12 Tubes measure 38mm, or 12 eighths of an inch, in diameter and are available in wattages ranging from 20-125 watts.
T2 is a term describing a tube that is 2 eighths of an inch in diameter, or 7mm.
A T2 Tube is a type of slimline fluorescent tube commonly used for Cabinet and Display lighting. Available in 6, 8, 11 or 13 watts the T2 tube has a distinguishable W4.3 Plug In base at each end.
T2 can also be used to describe certain types of energy saving lamps, such as Energy Saving Spirals.
A T4 Tube is a type of fluorescent tube commonly found in pelmet or under cabinet lighting due to their slimline design. The T4 tube is named so as it measures 4 eighths of an inch, or 14mm in diameter and is available in wattages ranging from 6 to 30 watts.
A T5, sometimes called the T16 is a common type of fluorescent tube predominantly found in recessed and suspended ceiling applications. The T5 tube gets its' name from being 5 eighths of an inch in diameter, or 15-16mm.
Although commonly referring to linear tubes, T5 tube could refer to a type of circular fluorescent tube. The T5 circular tube has a 2GX13 base with 2 pins either side of the tube.
T5 can also be used to describe 2D Compact Fluorescent Lamps. This is due to the diameter of the actual tube itself being 15mm, the same as the T5 Linear Tube.
A T8 Tube is a type of popular type of fluorescent tube favoured for its' versatility in application. The T8 tube is named so as it measures 8 eights of an inch in diameter, or 25mm.
T8 Fluorescent Tubes can now be replaced with LED alternatives, offering a longer life span and reduced power consumption.
USB, or Universal Serial Bus, is a term used to describe the industry standard for connecting peripherals to computers and other devices.
Wedge Base is a term used to describe low voltage capless capsule lamps. These lamps are commonly used in Garden, Automotive and Bicycle lighting applications.