Flashlight
Encyclopedia
A flashlight is a hand-held electric-powered light source. Usually the light source is a small incandescent lightbulb or light-emitting diode
(LED). Typical flashlight designs consist of the light source mounted in a reflector, a lens to protect the light source and reflector, a battery
or other power source, and a switch
.
In addition to the general-purpose hand-held flashlight, many forms have been adapted for special uses. Head or helmet-mounted flashlights designed for miners and campers
leave the hands free. Some flashlights can be used underwater or in flammable atmospheres.
battery was invented. Unlike previous batteries, it used a paste electrolyte instead of a liquid. This was the first battery suitable for portable electrical devices, as it did not spill or break easily and worked in any orientation. Portable hand-held electric lights offered advantages in convenience and safety over (combustion) torch
es, candle
s and lantern
s. The electric lamp was odorless, smokeless, and emitted less heat than combustion-powered lighting. It could be instantly turned on and off, and avoided fire risk.
On January 10, 1899, American Electrical Novelty and Manufacturing Company
obtained U.S. Patent No. 617,592 (filed 12 March 1898) from David Misell, its English inventor. This "electric device" designed by Misell was powered by "D" batteries laid front to back in a paper tube with the light bulb and a rough brass reflector at the end. The company donated some of these devices to the New York City police, who responded favorably to them.
These early flashlights ran on zinc–carbon batteries
, which could not provide a steady electric current and required periodic 'rest' to continue functioning. Because these early flashlights also used energy-inefficient carbon-filament bulbs, "resting" occurred at short intervals. Consequently, they could be used only in brief flashes, hence the popular name flashlight.
Carbon-filament bulbs and fairly crude dry cells made early flashlights an expensive novelty with low sales and low manufacturer interest. Development of the tungsten-filament lamp around 1906, with three times the efficacy of carbon filament types, and improved batteries, made flashlights more useful and popular. By 1922 several types were available; the tubular hand-held variety, a lantern style that could be set down for extended use, pocket size lamps for close work, and large reflector searchlight-type lamps for lighting distant objects. In 1922 there were an estimated 10 million flashlight users in the United States, with annual sales of renewal batteries and flashlights at $20 million, comparable to sales of many line-operated electrical appliances. Miniature lamps developed for flashlight and automotive uses became an important sector of the incandescent lamp manufacturing business.
s which consists of a glass bulb and a tungsten
filament. The bulbs are under vacuum or filled with argon
, krypton
or xenon
. Some high-power incandescent flashlight use a halogen lamp
where the bulb contains trace of halogen
such as iodine
or bromine
to improve the life and efficacy of the bulb.
The light output of an incandescent lamp in a flashlight varies widely depending on the type of lamp. A miniature keychain lamp produces one or two lumens. A two D-cell flashlight using a common prefocus-style miniature lamp will produce on the order of 15 to 20 lumen
s of light and a beam of about 200 candlepower
. One popular make
of rechargeable focusing flashlight uses a halogen lamp and produces 218 lumens. By comparison, a 60-watt household incandescent lamp will produce about 900 lumens.
s (LED)s have made practical flashlights that use LEDs instead of conventional light bulbs. LEDs have existed for decades, mainly used as low-power indicator lights. In 1999, Lumileds Corporation
of San Jose, California
United States, introduced the Luxeon LED, a high-power white-light emitter. This made possible LED flashlights with power and running time better than incandescent lights. The first Luxeon LED flashlight was the Arc LS
, designed in 2001.
LEDs can be significantly more efficient than incandescent lamps. An LED flashlight will have a longer battery life than a comparable incandescent flashlight. LEDs are also less fragile than conventional glass lamps. LED lamp
s have a different spectrum of light compared to incandescent sources, and are made in several ranges of color temperature
.
Some LED flashlights electronically regulate the voltage supplied to the LEDs to stabilize light output as the batteries discharge. By contrast, the light output of non-regulated flashlights declines as battery voltage declines. LEDs also have the advantage of maintaining nearly constant color temperature
regardless of input voltage or current, while the color temperature of an incandescent bulb rapidly declines as the battery discharges. Regulated LED flashlights may also have user-selectable levels of output appropriate to a task, for example, low light for reading a map and high output for checking a road sign. This would be difficult to do in an incandescent flashlight since efficacy of the lamp drops rapidly at low output.
LED flashlights may consume 1 watt or more from the battery, producing heat as well as light. Heat dissipation for the LED often dictates that LED flashlights have aluminum bodies to dissipate heat; they can become warm during use.
Light output from LED flashlights varies even more widely than for incandescent lights. "Keychain" type lamps operating on button batteries
, or lights using a single 5 mm LED, may only produce a couple of lumens. Even a small LED flashlight operating on an AA cell but equipped with a power LED can emit 100 lumens. The most powerful LED flashlights produce more than one thousand lumens and may use multiple power LEDs.
LEDs are highly efficient at producing colored light compared with incandescent lamps and filters. Colored LED flashlights are used for signalling, special inspection tasks, forensic examination, or to track the blood trail of wounded game animals. A flashlight may have a red LED intended to preserve dark adaption
of vision. Ultraviolet LEDs may be used for inspection lights, for example, detecting fluorescent dyes added to air conditioning systems to detect leakage, examining paper currency
, or checking UV-fluorescing marks on laundry or event ticketholders. Infrared LEDs can be used for illuminators for night vision systems.
as a filler.
HID lamps produce more light than an incandescent flashlight using the same amount of electricity. The lamp will last longer and is more shock resistant than a regular incandescent bulb, since it lacks the relatively fragile electrical filament found in incandescent bulbs. However, they are much more expensive, due to the ballast circuitry required to start and operate the lamp. An HID lamp requires a short warm-up time before it reaches full output.
A typical HID flashlight would have a 35 watt lamp and produce more than 3000 lumens.
Translucent colored plastic cones slipped over the lens of a flashlight increase the visibility when looking at the side of the light. Such marshalling wands are frequently used for directing automobiles or aircraft at night. Colored lenses placed over the end of the flashlight are used for signalling, for example, in railway yards. Colored light is occasionally useful for hunters tracking wounded game after dusk, or for forensic examination of an area. A red filter helps preserve night vision after the flashlight is turned off, and can be useful to observe animals (such as nesting Loggerhead sea turtle
s) without disturbing them.
-sized flashlight, often containing two AA batteries
or AAA batteries
. In some types the incandescent light bulb has an integral lens
that focuses the light, so no reflector is built into the penlight. Others use incandescent bulbs mounted in reflectors. LED
penlights are becoming increasingly common. Low-cost units may be disposable with no provision for the user to replace batteries or bulbs, and are sometimes imprinted with advertising for promotional purposes.
A headlamp
is designed to be worn on the head, often having separate lamp and battery components. The battery pack may be attached to the back of the head or in a pocket to improve balance. Headlamps leave the user's hands free, making them popular for recreational and occupational activities. Similar to the headlamp, an angle-head flashlight emits light perpendicular to the length of the battery tube; it can be clipped to a belt or webbing to leave the user's hands free, or set on a flat surface. Some types allow the user to adjust the angle of the head.
Sometimes a tactical light
is mounted to a handgun
or rifle
. Such lamps are designed to withstand the impact of recoil, and to be easily controlled while holding the weapon.
Although most flashlights are designed for user replacement of the batteries and the bulb as needed, fully sealed disposable
flashlights, such as inexpensive keyring lights, are made. When the batteries are depleted or the bulb fails, the entire product usually is thrown away or recycled and a new one purchased to replace it.
Diving lamps must be watertight under pressure and are used for night diving
and supplemental illumination where surface light cannot reach.
People working in hazardous areas
with significant concentrations of flammable gases or dusts, such as mines, engine rooms of ships, chemical plants or grain elevator
s, use "non-incendive", "intrinsically safe" or "explosion proof" flashlights. These are constructed so that any spark in the gas or dust that leaks into the flashlight is not likely to set off an explosion outside the light. The flashlight may require approval by an authority for the particular service and particular gases expected. The external temperature rise of the flashlight must not exceed the autoignition point of the gas, so substitution of more powerful lamps or batteries may void the approval.
Most flashlights are cylindrical in design, with the lamp assembly attached to one end. However, early designs came in a variety of shapes. Many resembled modern day lantern
s, consisting largely of a box with a handle and the lamp attached to the front. Some others were made to have a similar appearance to candle
s. Portable hand-held electric lantern
s can provide larger reflectors and lamps, and more powerful batteries
than tubular flashlights meant to fit in a pocket. They are often designed for lighting the broad area immediately around the lantern, as opposed to forming a narrow beam; they can be set down on a level surface or attached to supports. Some electric lanterns use miniature fluorescent lamp
s for higher efficacy than incandescent bulbs.
Flashlights may be temporarily mounted on handlebars for bicycle lighting
, although permanently mounted bicycle lamps are common.
Multifunction portable devices may include a flashlight as one of their features; for example, a portable radio/flashlight combination. Many smartphone
s have a button or software application available to turn up their screen backlights to full intensity, or to switch on the camera flash or video light, providing a "flashlight" function.
. Many types of batteries are suitable for use in flashlights, such as button cell
s, carbon-zinc batteries in both regular and heavy duty types, alkaline
, lithium
and rechargeable lead acid
batteries, NiMH
, NiCd
batteries and lithium ion batteries. The choice of batteries will depend on the light source used, and will usually play a determining role in the size and shape of the flashlight.
Primary cells are most economical for infrequent use; some types of primary cell can be stored for years, where flashlights are required only in emergencies. Flashlights used for extended periods every day may be more economical to run on rechargeable (secondary) batteries. Flashlights adapted for use with rechargeable batteries may include features to allow charging without removing the batteries from the light, for example, a light kept in a vehicle may be trickle-charged and always ready when needed. Power-failure lights are designed to keep their batteries charged from a wall plug and to automatically turn on after an AC power failure; the power-failure light can be removed from the wall socket and used as a portable flashlight. Solar powered flashlight
s use energy from a solar cell
to charge an on-board battery for later use.
At least one manufacturer makes a rechargeable flashlight that uses a supercapacitor
to store energy. The capacitor can be recharged more rapidly than a battery and can be recharged many times without loss of capacity; however, the running time is limited by the relative bulk of capacitors compared to electrochemical cells.
that charges a capacitor. Others generate electricity using electromagnetic induction
. They use a strong permanent magnet
that can freely slide up and down a tube, passing through a coil of wire as it does. Shaking the flashlight will charge a capacitor
or a rechargeable battery
that supplies a current to a light source. Such flashlights can be useful during an emergency, when utility power and batteries may not be available.
shape. This reflects the light emerging in all directions from the bulb into an approximately parallel beam. Some flashlights allow the user to adjust the position of the lamp, giving a variable-focus effect from a wide flood light to a narrow beam. The reflector is covered to keep out dirt and moisture, sometimes with just a flat transparent cover, but some designs use a plastic or glass "bulls-eye" lens to form a more concentrated beam. The lens or reflector cover must resist impacts and the heat of the lamp, and must not lose too much of the transmitted light to reflection or absorbtion. Reflectors may be made of polished metal, or glass or plastic with an aluminized reflective finish. Some manufacturers use a pebbled, instead of a smooth, reflector, to improve the uniformity of the light beam emitted. Where multiple LEDs are used, each one may be put in its own parabolic reflector.
Very small flashlights may not have a reflector or lens separate from the lamp. Some types of penlight incandescent bulb have a built-in glass lens. Small light-emitting diodes have a domed package that also acts as a lens.
, and the second contact was a moveable metal loop that could be flipped down to touch the ring, completing the circuit. A wide variety of mechanical switch designs using slide switches, rocker switches, or pushbuttons have been used in flashlights. A common combination is a slide switch that allows the light to be left on for an extended time, combined with a momentary button for intermittent use or signalling. Since voltages and currents are low, switch design is limited only by the available space and desired cost of production.
Electronic controls allow the user to select variable output levels or different operating modes such as pre-programmed flashing beacon or strobe modes. Electronic controls may be operated by buttons, sliders, magnets, or rotating control rings. One model of flashlight includes an acceleration sensor to allow it to respond to shaking. At least one manufacturer allows user programming of the features of the flashlight through a USB port.
and polyethylene
to more complex mixtures of ABS
or glass-reinforced epoxies. Some manufacturers have proprietary plastic formulations for their products. A desirable plastic for manufacturing flashlights allows for ease of molding and adequate mechanical properties of the finished flashlight case. Aluminum, either plain, painted or anodized, is a popular choice. It is electrically conductive, can be easily machined, and dissipates heat well. Several standard alloys of aluminum are used. Other metals include stainless steel
and titanium
, which can be polished to provide a decorative finish. Zinc can be die-cast into intricate shapes. Magnesium and its alloys provide strength and heat dissipation similar to aluminum and can also be die cast.
with flammable gas are tested for external temperature, and are tested to ensure they cannot set off an explosion. Flashlights approved for flammable gas areas will have markings indicating the approving agency (MHSA
, ATEX
, etc.) and symbols for the conditions that were tested.
Regulations for ships and aircraft will specify the number and general properties of flashlights included as part of the standard safety equipment of the vessel. Flashlights for small boats may be required to be waterproof and to float. Uniformed services may provide particular models of issue flashlight, or may only provide minimium performance standards for the member to purchase his or her own flashlights.
In the United States, ANSI
in 2009 published voluntary standard FL1 Flashlight basic performance standard, which standardizes the test procedures for total light output, beam intensity, working distance, impact and water resistance, and battery running time to 10% of initial light output. The FL1 standard gives standard definitions for terms used in marketing flashlights, and standard test conditions and procedures, with the intention of allowing the consumer to compare products tested to the standard. The standard recommends particular graphic symbols and wording for the product package, to allow the consumer to identify if the product has been tested to the standard. A test laboratory may charge US $2000 or more for a complete set of FL1 tests.
The FL1 standard requires measurements reported on the packaging to be made with the type of batteries packaged with the flashlight, or with an identified type of battery. Initial light output is measured with an integrating sphere
photometer, 30 seconds after the light is switched on with fresh (or newly charged) batteries; the total light emitted is reported in lumen
s. Beam intensity is determined by measuring the brightest spot in the beam produced by the flashlight, in candela
s; since this is a measure of the light emitted in a solid angle, the beam intensity is independent of distance. The working distance is defined as the distance at which the maximum illuminance
(light falling on a surface) would fall to 0.25 lux
; this is a level of illuminance comparable to a full moon on a clear night. It is calculated from the square root of the beam intensity in candelas divided by 0.25 lux; for example, a beam intensity of 1000 candelas produces a working range rating of 63 metres. The result is reported in metres or converted to feet.
Run time is measured using the supplied or specified batteries and letting the light run until the intensity of the beam has dropped to 10% of the value 30 seconds after switching on. The standard does not evaluate the behavior of the flashlight output during run time; a regulated flashlight may run at only a slowly declining output and then abruptly cut off, but unregulated types may have steeply-declining light output after only a short time.
Impact resistance is measured by dropping the flashlight in six different orientations and observing that it still functions and has no large cracks or breaks in it; the height used in the test is reported. Water resistance, if specified, is evaluated after impact testing; no water is to be visible inside the unit and it must remain functional after either a brief immersion (IP Code IPX7) or after 30 minutes immersion at 1 metre or more (IP X8); the depth is reported if greater than 1 metre.
LED lamp
An LED lamp is a solid-state lamp that uses light-emitting diodes as the source of light. The LEDs involved may be conventional semiconductor light-emitting diodes, organic LEDs , or polymer light-emitting diodes devices, although PLED technologies are not currently commercially available.Since...
(LED). Typical flashlight designs consist of the light source mounted in a reflector, a lens to protect the light source and reflector, a battery
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
or other power source, and a switch
Switch
In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....
.
In addition to the general-purpose hand-held flashlight, many forms have been adapted for special uses. Head or helmet-mounted flashlights designed for miners and campers
Camping
Camping is an outdoor recreational activity. The participants leave urban areas, their home region, or civilization and enjoy nature while spending one or several nights outdoors, usually at a campsite. Camping may involve the use of a tent, caravan, motorhome, cabin, a primitive structure, or no...
leave the hands free. Some flashlights can be used underwater or in flammable atmospheres.
History
In 1896, the first dry cellDry Cell
-Dry Cell's formation:Part of the band formed in 1998 when guitarist Danny Hartwell and drummer Brandon Brown met at the Ratt Show on the Sunset Strip. They later met up with then-vocalist Judd Gruenbaum. The original name of the band was "Beyond Control"....
battery was invented. Unlike previous batteries, it used a paste electrolyte instead of a liquid. This was the first battery suitable for portable electrical devices, as it did not spill or break easily and worked in any orientation. Portable hand-held electric lights offered advantages in convenience and safety over (combustion) torch
Torch
A torch is a fire source, usually a rod-shaped piece of wood with a rag soaked in pitch and/or some other flammable material wrapped around one end. Torches were often supported in sconces by brackets high up on walls, to throw light over corridors in stone structures such as castles or crypts...
es, candle
Candle
A candle is a solid block or cylinder of wax with an embedded wick, which is lit to provide light, and sometimes heat.Today, most candles are made from paraffin. Candles can also be made from beeswax, soy, other plant waxes, and tallow...
s and lantern
Lantern
A lantern is a portable lighting device or mounted light fixture used to illuminate broad areas. Lanterns may also be used for signaling, as 'torches', or as general light sources outdoors . Low light level varieties are used for decoration. The term "lantern" is also used more generically to...
s. The electric lamp was odorless, smokeless, and emitted less heat than combustion-powered lighting. It could be instantly turned on and off, and avoided fire risk.
On January 10, 1899, American Electrical Novelty and Manufacturing Company
Energizer Holdings
Energizer Holdings is an American manufacturer of batteries and personal care products, headquartered in Town and Country, Missouri. Its most well known brands are Energizer and Eveready batteries, Schick, Wilkinson Sword and Edge shaving products, Playtex feminine hygiene and baby products, and...
obtained U.S. Patent No. 617,592 (filed 12 March 1898) from David Misell, its English inventor. This "electric device" designed by Misell was powered by "D" batteries laid front to back in a paper tube with the light bulb and a rough brass reflector at the end. The company donated some of these devices to the New York City police, who responded favorably to them.
These early flashlights ran on zinc–carbon batteries
Zinc-carbon battery
A zinc–carbon dry cell or battery is packaged in a zinc can that serves as both a container and negative terminal. It was developed from the wet Leclanché cell . The positive terminal is a carbon rod surrounded by a mixture of manganese dioxide and carbon powder. The electrolyte used is a paste of...
, which could not provide a steady electric current and required periodic 'rest' to continue functioning. Because these early flashlights also used energy-inefficient carbon-filament bulbs, "resting" occurred at short intervals. Consequently, they could be used only in brief flashes, hence the popular name flashlight.
Carbon-filament bulbs and fairly crude dry cells made early flashlights an expensive novelty with low sales and low manufacturer interest. Development of the tungsten-filament lamp around 1906, with three times the efficacy of carbon filament types, and improved batteries, made flashlights more useful and popular. By 1922 several types were available; the tubular hand-held variety, a lantern style that could be set down for extended use, pocket size lamps for close work, and large reflector searchlight-type lamps for lighting distant objects. In 1922 there were an estimated 10 million flashlight users in the United States, with annual sales of renewal batteries and flashlights at $20 million, comparable to sales of many line-operated electrical appliances. Miniature lamps developed for flashlight and automotive uses became an important sector of the incandescent lamp manufacturing business.
Incandescent
Incandescent flashlights use incandescent light bulbIncandescent light bulb
The incandescent light bulb, incandescent lamp or incandescent light globe makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process...
s which consists of a glass bulb and a tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...
filament. The bulbs are under vacuum or filled with argon
Argon
Argon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...
, krypton
Krypton
Krypton is a chemical element with the symbol Kr and atomic number 36. It is a member of Group 18 and Period 4 elements. A colorless, odorless, tasteless noble gas, krypton occurs in trace amounts in the atmosphere, is isolated by fractionally distilling liquified air, and is often used with other...
or xenon
Xenon
Xenon is a chemical element with the symbol Xe and atomic number 54. The element name is pronounced or . A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts...
. Some high-power incandescent flashlight use a halogen lamp
Halogen lamp
A halogen lamp, also known as a tungsten halogen lamp, is an incandescent lamp with a tungsten filament contained within an inert gas and a small amount of a halogen such as iodine or bromine. The chemical halogen cycle redeposits evaporated tungsten back on to the filament, extending the life of...
where the bulb contains trace of halogen
Halogen
The halogens or halogen elements are a series of nonmetal elements from Group 17 IUPAC Style of the periodic table, comprising fluorine , chlorine , bromine , iodine , and astatine...
such as iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
or bromine
Bromine
Bromine ") is a chemical element with the symbol Br, an atomic number of 35, and an atomic mass of 79.904. It is in the halogen element group. The element was isolated independently by two chemists, Carl Jacob Löwig and Antoine Jerome Balard, in 1825–1826...
to improve the life and efficacy of the bulb.
The light output of an incandescent lamp in a flashlight varies widely depending on the type of lamp. A miniature keychain lamp produces one or two lumens. A two D-cell flashlight using a common prefocus-style miniature lamp will produce on the order of 15 to 20 lumen
Lumen (unit)
The lumen is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux...
s of light and a beam of about 200 candlepower
Candlepower
Candlepower is a now-obsolete unit which was used to express levels of light intensity in terms of the light emitted by a candle of specific size and constituents...
. One popular make
Maglite
Maglite is a brand of flashlight manufactured in the United States by Mag Instrument, Inc. located in Ontario, California, and founded by Anthony Maglica. It was introduced in 1979. Constructed principally of anodized 6061 aluminum, they have a variable-focus beam...
of rechargeable focusing flashlight uses a halogen lamp and produces 218 lumens. By comparison, a 60-watt household incandescent lamp will produce about 900 lumens.
LED
Developments in light-emitting diodeLED lamp
An LED lamp is a solid-state lamp that uses light-emitting diodes as the source of light. The LEDs involved may be conventional semiconductor light-emitting diodes, organic LEDs , or polymer light-emitting diodes devices, although PLED technologies are not currently commercially available.Since...
s (LED)s have made practical flashlights that use LEDs instead of conventional light bulbs. LEDs have existed for decades, mainly used as low-power indicator lights. In 1999, Lumileds Corporation
Philips Lumileds Lighting Company
Philips Lumileds Lighting Company is the manufacturer of a wide range of high-power/high-efficiency light-emitting diodes . It is a now a fully owned division of Philips Lighting.-History:...
of San Jose, California
San Jose, California
San Jose is the third-largest city in California, the tenth-largest in the U.S., and the county seat of Santa Clara County which is located at the southern end of San Francisco Bay...
United States, introduced the Luxeon LED, a high-power white-light emitter. This made possible LED flashlights with power and running time better than incandescent lights. The first Luxeon LED flashlight was the Arc LS
Arc Flashlight
Arc Flashlight LLC was an American manufacturer that produced innovative LED flashlights. Arc Flashlight LLC began operation May 2001, and went out of business September 22, 2004...
, designed in 2001.
LEDs can be significantly more efficient than incandescent lamps. An LED flashlight will have a longer battery life than a comparable incandescent flashlight. LEDs are also less fragile than conventional glass lamps. LED lamp
LED lamp
An LED lamp is a solid-state lamp that uses light-emitting diodes as the source of light. The LEDs involved may be conventional semiconductor light-emitting diodes, organic LEDs , or polymer light-emitting diodes devices, although PLED technologies are not currently commercially available.Since...
s have a different spectrum of light compared to incandescent sources, and are made in several ranges of color temperature
Color temperature
Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of...
.
Some LED flashlights electronically regulate the voltage supplied to the LEDs to stabilize light output as the batteries discharge. By contrast, the light output of non-regulated flashlights declines as battery voltage declines. LEDs also have the advantage of maintaining nearly constant color temperature
Color temperature
Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of...
regardless of input voltage or current, while the color temperature of an incandescent bulb rapidly declines as the battery discharges. Regulated LED flashlights may also have user-selectable levels of output appropriate to a task, for example, low light for reading a map and high output for checking a road sign. This would be difficult to do in an incandescent flashlight since efficacy of the lamp drops rapidly at low output.
LED flashlights may consume 1 watt or more from the battery, producing heat as well as light. Heat dissipation for the LED often dictates that LED flashlights have aluminum bodies to dissipate heat; they can become warm during use.
Light output from LED flashlights varies even more widely than for incandescent lights. "Keychain" type lamps operating on button batteries
Button cell
A watch battery or button cell is a small single cell battery shaped as a squat cylinder typically 5 to 12 mm in diameter and 1 to 6 mm high—like a button on a garment, hence the name. Button cells are used to power small portable electronics devices such as wrist watches, pocket...
, or lights using a single 5 mm LED, may only produce a couple of lumens. Even a small LED flashlight operating on an AA cell but equipped with a power LED can emit 100 lumens. The most powerful LED flashlights produce more than one thousand lumens and may use multiple power LEDs.
LEDs are highly efficient at producing colored light compared with incandescent lamps and filters. Colored LED flashlights are used for signalling, special inspection tasks, forensic examination, or to track the blood trail of wounded game animals. A flashlight may have a red LED intended to preserve dark adaption
Adaptation (eye)
In ocular physiology, adaptation is the ability of the eye to adjust to various levels of darkness and light.-Efficacy:The human eye can function from very dark to very bright levels of light; its sensing capabilities reach across nine orders of magnitude. This means that the brightest and the...
of vision. Ultraviolet LEDs may be used for inspection lights, for example, detecting fluorescent dyes added to air conditioning systems to detect leakage, examining paper currency
Currency
In economics, currency refers to a generally accepted medium of exchange. These are usually the coins and banknotes of a particular government, which comprise the physical aspects of a nation's money supply...
, or checking UV-fluorescing marks on laundry or event ticketholders. Infrared LEDs can be used for illuminators for night vision systems.
HID
Another less common type of flashlight uses a High Intensity Discharge (HID) lamp as the light source. HID is a type of gas discharge lamp that uses a mixture of metal halide salts and argonArgon
Argon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...
as a filler.
HID lamps produce more light than an incandescent flashlight using the same amount of electricity. The lamp will last longer and is more shock resistant than a regular incandescent bulb, since it lacks the relatively fragile electrical filament found in incandescent bulbs. However, they are much more expensive, due to the ballast circuitry required to start and operate the lamp. An HID lamp requires a short warm-up time before it reaches full output.
A typical HID flashlight would have a 35 watt lamp and produce more than 3000 lumens.
Accessories
Certain accessories for a flashlight allow the color of the light to be altered or allow light to be dispersed differently.Translucent colored plastic cones slipped over the lens of a flashlight increase the visibility when looking at the side of the light. Such marshalling wands are frequently used for directing automobiles or aircraft at night. Colored lenses placed over the end of the flashlight are used for signalling, for example, in railway yards. Colored light is occasionally useful for hunters tracking wounded game after dusk, or for forensic examination of an area. A red filter helps preserve night vision after the flashlight is turned off, and can be useful to observe animals (such as nesting Loggerhead sea turtle
Loggerhead sea turtle
The loggerhead sea turtle , or loggerhead, is an oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around long when fully grown, although larger specimens of up to have been discovered...
s) without disturbing them.
Formats and specialized designs
A penlight is a small, penPen
A pen is a device used to apply ink to a surface, usually paper, for writing or drawing. Historically, reed pens, quill pens, and dip pens were used, with a nib of some sort to be dipped in the ink. Ruling pens allow precise adjustment of line width, and still find a few specialized uses, but...
-sized flashlight, often containing two AA batteries
AA battery
An AA battery is a standard size of battery. Batteries of this size are the most commonly used type of in portable electronic devices. An AA battery is composed of a single electrochemical cell...
or AAA batteries
AAA battery
A triple A or AAA battery is a standard size of dry cell battery commonly used in portable electronic devices. A carbon-zinc battery in this size is designated by IEC as "R03", by ANSI C18.1 as "24", by old JIS standard as "UM 4", and by other manufacturer and national standard designations that...
. In some types the incandescent light bulb has an integral lens
Lens (optics)
A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens consists of a single optical element...
that focuses the light, so no reflector is built into the penlight. Others use incandescent bulbs mounted in reflectors. LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
penlights are becoming increasingly common. Low-cost units may be disposable with no provision for the user to replace batteries or bulbs, and are sometimes imprinted with advertising for promotional purposes.
A headlamp
Headlamp (outdoor)
A headlamp is a light source affixed to the head for outdoor activities at night or in dark conditions such as caving, orienteering, hiking, backpacking, camping, mountaineering or mountain biking...
is designed to be worn on the head, often having separate lamp and battery components. The battery pack may be attached to the back of the head or in a pocket to improve balance. Headlamps leave the user's hands free, making them popular for recreational and occupational activities. Similar to the headlamp, an angle-head flashlight emits light perpendicular to the length of the battery tube; it can be clipped to a belt or webbing to leave the user's hands free, or set on a flat surface. Some types allow the user to adjust the angle of the head.
Sometimes a tactical light
Tactical light
A tactical light is a flashlight used in conjunction with a firearm to aid low light target identification, allowing the marksman to simultaneously aim and illuminate the target. Tactical lights can be handheld or mounted to the weapon with the light beam parallel to the bore...
is mounted to a handgun
Handgun
A handgun is a firearm designed to be held and operated by one hand. This characteristic differentiates handguns as a general class of firearms from long guns such as rifles and shotguns ....
or rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...
. Such lamps are designed to withstand the impact of recoil, and to be easily controlled while holding the weapon.
Although most flashlights are designed for user replacement of the batteries and the bulb as needed, fully sealed disposable
Disposable
A disposable is a product designed for cheapness and short-term convenience rather than medium to long-term durability, with most products only intended for single use. The term is also sometimes used for products that may last several months to distinguish from similar products that last...
flashlights, such as inexpensive keyring lights, are made. When the batteries are depleted or the bulb fails, the entire product usually is thrown away or recycled and a new one purchased to replace it.
Diving lamps must be watertight under pressure and are used for night diving
Night diving
Night diving is a type of recreational diving which takes place in darkness. The diver can experience a different underwater environment at night, because many marine animals are nocturnal....
and supplemental illumination where surface light cannot reach.
People working in hazardous areas
Electrical Equipment in Hazardous Areas
In electrical engineering, a hazardous location is defined as a place where concentrations of flammable gases, vapors, or dusts occur. Electrical equipment that must be installed in such locations is especially designed and tested to ensure it does not initiate an explosion, due to arcing contacts...
with significant concentrations of flammable gases or dusts, such as mines, engine rooms of ships, chemical plants or grain elevator
Grain elevator
A grain elevator is a tower containing a bucket elevator, which scoops up, elevates, and then uses gravity to deposit grain in a silo or other storage facility...
s, use "non-incendive", "intrinsically safe" or "explosion proof" flashlights. These are constructed so that any spark in the gas or dust that leaks into the flashlight is not likely to set off an explosion outside the light. The flashlight may require approval by an authority for the particular service and particular gases expected. The external temperature rise of the flashlight must not exceed the autoignition point of the gas, so substitution of more powerful lamps or batteries may void the approval.
Most flashlights are cylindrical in design, with the lamp assembly attached to one end. However, early designs came in a variety of shapes. Many resembled modern day lantern
Lantern
A lantern is a portable lighting device or mounted light fixture used to illuminate broad areas. Lanterns may also be used for signaling, as 'torches', or as general light sources outdoors . Low light level varieties are used for decoration. The term "lantern" is also used more generically to...
s, consisting largely of a box with a handle and the lamp attached to the front. Some others were made to have a similar appearance to candle
Candle
A candle is a solid block or cylinder of wax with an embedded wick, which is lit to provide light, and sometimes heat.Today, most candles are made from paraffin. Candles can also be made from beeswax, soy, other plant waxes, and tallow...
s. Portable hand-held electric lantern
Lantern
A lantern is a portable lighting device or mounted light fixture used to illuminate broad areas. Lanterns may also be used for signaling, as 'torches', or as general light sources outdoors . Low light level varieties are used for decoration. The term "lantern" is also used more generically to...
s can provide larger reflectors and lamps, and more powerful batteries
Lantern battery
A lantern battery is a rectangular, alkaline or zinc-carbon primary battery used primarily in flashlights or lanterns. Lantern batteries are physically larger and consequently offer higher capacity than the more common torch batteries...
than tubular flashlights meant to fit in a pocket. They are often designed for lighting the broad area immediately around the lantern, as opposed to forming a narrow beam; they can be set down on a level surface or attached to supports. Some electric lanterns use miniature fluorescent lamp
Fluorescent lamp
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful...
s for higher efficacy than incandescent bulbs.
Flashlights may be temporarily mounted on handlebars for bicycle lighting
Bicycle lighting
Bicycle lighting improves the visibility of the bicycle rider to others in dark conditions, i.e. to increase the rider's conspicuity and to enhance the ability of the rider to see, illuminating the way forward. Both reflectors and active lights are used to make the rider more visible, and many ...
, although permanently mounted bicycle lamps are common.
Multifunction portable devices may include a flashlight as one of their features; for example, a portable radio/flashlight combination. Many smartphone
Smartphone
A smartphone is a high-end mobile phone built on a mobile computing platform, with more advanced computing ability and connectivity than a contemporary feature phone. The first smartphones were devices that mainly combined the functions of a personal digital assistant and a mobile phone or camera...
s have a button or software application available to turn up their screen backlights to full intensity, or to switch on the camera flash or video light, providing a "flashlight" function.
Batteries
The most common power source for flashlights is the batteryBattery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
. Many types of batteries are suitable for use in flashlights, such as button cell
Button cell
A watch battery or button cell is a small single cell battery shaped as a squat cylinder typically 5 to 12 mm in diameter and 1 to 6 mm high—like a button on a garment, hence the name. Button cells are used to power small portable electronics devices such as wrist watches, pocket...
s, carbon-zinc batteries in both regular and heavy duty types, alkaline
Alkaline battery
Alkaline batteries are a type of primary batteries dependent upon the reaction between zinc and manganese dioxide . A rechargeable alkaline battery allows reuse of specially designed cells....
, lithium
Lithium battery
Lithium batteries are disposable batteries that have lithium metal or lithium compounds as an anode. Depending on the design and chemical compounds used, lithium cells can produce voltages from 1.5 V to about 3.7 V, over twice the voltage of an ordinary zinc–carbon battery or alkaline battery...
and rechargeable lead acid
Lead-acid battery
Lead–acid batteries, invented in 1859 by French physicist Gaston Planté, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large...
batteries, NiMH
Nickel metal hydride battery
A nickel–metal hydride cell, abbreviated NiMH, is a type of rechargeable battery similar to the nickel–cadmium cell. The NiMH battery uses a hydrogen-absorbing alloy for the negative electrode instead of cadmium. As in NiCd cells, the positive electrode is nickel oxyhydroxide...
, NiCd
Nickel-cadmium battery
The nickel–cadmium battery ' is a type of rechargeable battery using nickel oxide hydroxide and metallic cadmium as electrodes....
batteries and lithium ion batteries. The choice of batteries will depend on the light source used, and will usually play a determining role in the size and shape of the flashlight.
Primary cells are most economical for infrequent use; some types of primary cell can be stored for years, where flashlights are required only in emergencies. Flashlights used for extended periods every day may be more economical to run on rechargeable (secondary) batteries. Flashlights adapted for use with rechargeable batteries may include features to allow charging without removing the batteries from the light, for example, a light kept in a vehicle may be trickle-charged and always ready when needed. Power-failure lights are designed to keep their batteries charged from a wall plug and to automatically turn on after an AC power failure; the power-failure light can be removed from the wall socket and used as a portable flashlight. Solar powered flashlight
Solar powered flashlight
Solar powered flashlights are flashlights that can be powered through solar energy using solar cells as well as through batteries. Most of these flashlights run on LED lights due to the low energy consumption cost.- Features :...
s use energy from a solar cell
Solar cell
A solar cell is a solid state electrical device that converts the energy of light directly into electricity by the photovoltaic effect....
to charge an on-board battery for later use.
At least one manufacturer makes a rechargeable flashlight that uses a supercapacitor
Supercapacitor
An electric double-layer capacitor , also known as supercapacitor, supercondenser, electrochemical double layer capacitor, or ultracapacitor, is an electrochemical capacitor with relatively high energy density. Their energy density is typically hundreds of times greater than conventional...
to store energy. The capacitor can be recharged more rapidly than a battery and can be recharged many times without loss of capacity; however, the running time is limited by the relative bulk of capacitors compared to electrochemical cells.
Mechanical power
One type of dynamo-powered flashlight has a winding crank and spring connected to a small electrical generatorElectrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
that charges a capacitor. Others generate electricity using electromagnetic induction
Electromagnetic induction
Electromagnetic induction is the production of an electric current across a conductor moving through a magnetic field. It underlies the operation of generators, transformers, induction motors, electric motors, synchronous motors, and solenoids....
. They use a strong permanent magnet
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.A permanent magnet is an object...
that can freely slide up and down a tube, passing through a coil of wire as it does. Shaking the flashlight will charge a capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
or a rechargeable battery
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
that supplies a current to a light source. Such flashlights can be useful during an emergency, when utility power and batteries may not be available.
Reflectors and lenses
To concentrate the light emitted by the bulb into a directed beam, a reflector is used, with an approximately parabolicParabola
In mathematics, the parabola is a conic section, the intersection of a right circular conical surface and a plane parallel to a generating straight line of that surface...
shape. This reflects the light emerging in all directions from the bulb into an approximately parallel beam. Some flashlights allow the user to adjust the position of the lamp, giving a variable-focus effect from a wide flood light to a narrow beam. The reflector is covered to keep out dirt and moisture, sometimes with just a flat transparent cover, but some designs use a plastic or glass "bulls-eye" lens to form a more concentrated beam. The lens or reflector cover must resist impacts and the heat of the lamp, and must not lose too much of the transmitted light to reflection or absorbtion. Reflectors may be made of polished metal, or glass or plastic with an aluminized reflective finish. Some manufacturers use a pebbled, instead of a smooth, reflector, to improve the uniformity of the light beam emitted. Where multiple LEDs are used, each one may be put in its own parabolic reflector.
Very small flashlights may not have a reflector or lens separate from the lamp. Some types of penlight incandescent bulb have a built-in glass lens. Small light-emitting diodes have a domed package that also acts as a lens.
Control switch
The original 1890's flashlights used a metal ring around the fiber body of the flashlight as one contact of a switchSwitch
In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....
, and the second contact was a moveable metal loop that could be flipped down to touch the ring, completing the circuit. A wide variety of mechanical switch designs using slide switches, rocker switches, or pushbuttons have been used in flashlights. A common combination is a slide switch that allows the light to be left on for an extended time, combined with a momentary button for intermittent use or signalling. Since voltages and currents are low, switch design is limited only by the available space and desired cost of production.
Electronic controls allow the user to select variable output levels or different operating modes such as pre-programmed flashing beacon or strobe modes. Electronic controls may be operated by buttons, sliders, magnets, or rotating control rings. One model of flashlight includes an acceleration sensor to allow it to respond to shaking. At least one manufacturer allows user programming of the features of the flashlight through a USB port.
Materials
Early flashlights used vulcanized fiber or hard rubber tubes with metal end caps. Since their invention, many other materials have been used. Drawn steel, plated brass, copper, silver, even wood and leather have been used. Modern flashlights are generally made of plastic or aluminum. Plastics range from low-cost polystyrenePolystyrene
Polystyrene ) also known as Thermocole, abbreviated following ISO Standard PS, is an aromatic polymer made from the monomer styrene, a liquid hydrocarbon that is manufactured from petroleum by the chemical industry...
and polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
to more complex mixtures of ABS
Acrylonitrile butadiene styrene
Acrylonitrile butadiene styrene is a common thermoplastic. Its melting point is approximately 105 °C ....
or glass-reinforced epoxies. Some manufacturers have proprietary plastic formulations for their products. A desirable plastic for manufacturing flashlights allows for ease of molding and adequate mechanical properties of the finished flashlight case. Aluminum, either plain, painted or anodized, is a popular choice. It is electrically conductive, can be easily machined, and dissipates heat well. Several standard alloys of aluminum are used. Other metals include stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
and titanium
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
, which can be polished to provide a decorative finish. Zinc can be die-cast into intricate shapes. Magnesium and its alloys provide strength and heat dissipation similar to aluminum and can also be die cast.
Ratings and standards
Industrial, marine, public safety and military organizations develop specifications for flashlights in specialized roles. Typically, light output, overall dimensions, battery compatibility and durability are required to meet minimum limits. Flashlights may be tested for impact resistance, water and chemical resistance, and for the life span of the control switch. Flashlights intended for use in hazardous areasElectrical Equipment in Hazardous Areas
In electrical engineering, a hazardous location is defined as a place where concentrations of flammable gases, vapors, or dusts occur. Electrical equipment that must be installed in such locations is especially designed and tested to ensure it does not initiate an explosion, due to arcing contacts...
with flammable gas are tested for external temperature, and are tested to ensure they cannot set off an explosion. Flashlights approved for flammable gas areas will have markings indicating the approving agency (MHSA
MHSA
The acronym MHSA can refer to* California Mental Health Services Act* Master of Health Services Administration, a graduate degree* Milwaukee High School of the Arts* Montana High School Association-External links:* in Acronym Finder...
, ATEX
Atex
Atex is a company specializing in the development of advertising and content management systems. The company was established in Massachusetts in 1973 and grew to become a worldwide software supplier to the publishing industry...
, etc.) and symbols for the conditions that were tested.
Regulations for ships and aircraft will specify the number and general properties of flashlights included as part of the standard safety equipment of the vessel. Flashlights for small boats may be required to be waterproof and to float. Uniformed services may provide particular models of issue flashlight, or may only provide minimium performance standards for the member to purchase his or her own flashlights.
In the United States, ANSI
Ansi
Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....
in 2009 published voluntary standard FL1 Flashlight basic performance standard, which standardizes the test procedures for total light output, beam intensity, working distance, impact and water resistance, and battery running time to 10% of initial light output. The FL1 standard gives standard definitions for terms used in marketing flashlights, and standard test conditions and procedures, with the intention of allowing the consumer to compare products tested to the standard. The standard recommends particular graphic symbols and wording for the product package, to allow the consumer to identify if the product has been tested to the standard. A test laboratory may charge US $2000 or more for a complete set of FL1 tests.
The FL1 standard requires measurements reported on the packaging to be made with the type of batteries packaged with the flashlight, or with an identified type of battery. Initial light output is measured with an integrating sphere
Integrating sphere
An Integrating sphere is an optical component consisting of a hollow cavity with its interior coated for high diffuse reflectivity , having relatively small holes as needed for entrance and exit ports....
photometer, 30 seconds after the light is switched on with fresh (or newly charged) batteries; the total light emitted is reported in lumen
Lumen
Lumen can mean:* Lumen , the SI unit of luminous flux* Lumen , the cavity or channel within a tubular structure* Thylakoid lumen, the inner membrane space of the chloroplast* Phenobarbital...
s. Beam intensity is determined by measuring the brightest spot in the beam produced by the flashlight, in candela
Candela
The candela is the SI base unit of luminous intensity; that is, power emitted by a light source in a particular direction, weighted by the luminosity function . A common candle emits light with a luminous intensity of roughly one candela...
s; since this is a measure of the light emitted in a solid angle, the beam intensity is independent of distance. The working distance is defined as the distance at which the maximum illuminance
Illuminance
In photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with human brightness perception. Similarly, luminous emittance is the luminous flux per...
(light falling on a surface) would fall to 0.25 lux
Lux
The lux is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface...
; this is a level of illuminance comparable to a full moon on a clear night. It is calculated from the square root of the beam intensity in candelas divided by 0.25 lux; for example, a beam intensity of 1000 candelas produces a working range rating of 63 metres. The result is reported in metres or converted to feet.
Run time is measured using the supplied or specified batteries and letting the light run until the intensity of the beam has dropped to 10% of the value 30 seconds after switching on. The standard does not evaluate the behavior of the flashlight output during run time; a regulated flashlight may run at only a slowly declining output and then abruptly cut off, but unregulated types may have steeply-declining light output after only a short time.
Impact resistance is measured by dropping the flashlight in six different orientations and observing that it still functions and has no large cracks or breaks in it; the height used in the test is reported. Water resistance, if specified, is evaluated after impact testing; no water is to be visible inside the unit and it must remain functional after either a brief immersion (IP Code IPX7) or after 30 minutes immersion at 1 metre or more (IP X8); the depth is reported if greater than 1 metre.
See also
- Carbide lampCarbide lampCarbide lamps, properly known as acetylene gas lamps, are simple lamps that produce and burn acetylene which is created by the reaction of calcium carbide with water....
- Dyno torch
- HeadlampHeadlampA headlamp is a lamp, usually attached to the front of a vehicle such as a car or a motorcycle, with the purpose of illuminating the road ahead during periods of low visibility, such as darkness or precipitation. Headlamp performance has steadily improved throughout the automobile age, spurred by...
for automobile lighting - Helmet light mountHelmet Light MountA helmet light mount is a small apparatus that is used to hold a flashlight to a hard hat. When working in dark construction zones, workers find it necessary to use a light to see what they are doing. The mount device frees their hands to continue working rather than being required to hold the...
- Safety lampSafety lampA safety lamp is any of several types of lamp, which are designed to be safe to use in coal mines. These lamps are designed to operate in air that may contain coal dust, methane, or firedamp, all of which are potentially flammable or explosive...
- SearchlightSearchlightA searchlight is an apparatus that combines a bright light source with some form of curved reflector or other optics to project a powerful beam of light of approximately parallel rays in a particular direction, usually constructed so that it can be swiveled about.-Military use:The Royal Navy used...
- SpotlightingSpotlightingSpotlighting or Lamping is a method of hunting nocturnal animals using off-road vehicles and high-powered lights, spotlights, lamps or flashlights, that makes special use of the eyeshine revealed by many animal species. A further important aspect is that many animals Spotlighting or Lamping (also...