How t o Choose t he Right F lashlight
Flashlights now come in so many choices of styles, features, battery and bulb types that
it is a task to figure out which flashlight will best suit your needs. Do you need
rechargeable or disposable batteries? Which bulb—xenon, krypton, halogen, LED or
standard incandescent—will best suit your application? Will you be in a hazardous
location or situation where a hazardous location rated flashlight is needed? Following
are breakdowns of the different flashlight options to help you decide.
Battery Ty pes
Rechargeable vs. Disposable: The situation can determine which type of battery is
needed. Disposable batteries are usually lower in initial purchase price, which makes it
easier to keep spares on hand. Typically, they are not as bright as rechargeables.
Rechargeable batteries have a higher initial purchase price but are more economical to
operate in the long run. They can often support a brighter bulb or LED and store
conveniently in custom charger holders. The following information can help determine
which type of battery is best for your use.
Alkaline—Are fairly inexpensive. However, performance is affected by heat and cold
and the power curve drops off very quickly. They are at their brightest the first time they
are used and decline rapidly thereafter.
Lithium—Becoming more and more affordable. They are not affected by extreme heat
and cold. They have a steady power curve over the life of the battery and have an
extremely long shelf life of nearly 10 years.
(Nickel-Cadmium or Ni- Cd) —Is the most rugged rechargeable technology and
proides the highest performance/cost ratio. New technology makes this battery more
and more effective. This type must be fully charged so it does not develop a memory
effect (does that at the bottom of the cycle and may occur as battery ages). These are
rechargeable up to 1000 times. Must be recycled or disposed of properly.
Lithium Ion—Rechargeable up to 1000 times with no memory effect problems. These
batteries have a longer runtime and are more expensive than standard lithium batteries.
They are environmentally friendly and can be thrown away.
Sealed Lead Acid—Like a car battery. Not affected by heat or cold. Sealed lead acid
batteries give extremely long runtimes but are fairly large in size. This type must be
recycled or disposed of properly.
Bulb Ty pes
A big difference among flashlights is the bulb used and the light it projects. Also
considered when choosing the bulb is longevity, cost and runtime of the bulbs. The
different bulb types are described below.
Incandescent Bulb Types:
Krypton Bulb—Incandescent bulb filled with krypton gas. A very economical bulb but
not as bright as a xenon or halogen bulb.
Xenon Bulb — Incandescent bi-pin bulb filled with xenon gas. This bulb provides
extremely bright light and is easily replaced. Xenon bulbs represent a good balance
between cost and output.
Halogen Bulb—Incandescent bulb filled with halogen gas. These are whiter and
brighter than other incandescent bulbs.
Both xenon and halogen lamps provide high output for their size and a white, natural-
appearing light. Halogen lamps “blacken” less as they age and may have longer life
than xenon. Both require periodic replacement and can fail on extreme impact. They are
easily focused and are the most powerful, highest performance, top choice for long
LED (Light Emitting Diodes) Types:
LEDs are a computer chip-like device that emits light when power is added. The LED
projects a wider, more dispersed light of 180 degrees. Solid-state construction makes
LEDs very durable and long-lived—up to 100,000 hours of life. LEDs do not require
periodic replacement like krypton, xenon and halogen lamps.
Due to their soft focus and short range, LEDs are good for close work. Typically, LEDs
provide much less power than incandescent lamps but offer the advantages of
extremely long runtimes (hundreds of hours) at low illumination levels, unlike a xenon or
halogen lamp that may have, at best, 5 to 9 hours of runtime. These solid-state lamps
are also safer in hazardous environments.
Tactical flashlights are typically more rugged, more reliable and more powerful than the
standard flashlight. Tactical-rated lights can be used as add-on lighting to weapons or
used on their own as a flashlight. These are used by the military, SWAT teams and
police forces for that reason.
With the above information on bulb and battery types, you can now ask yourself the
following questions to help select the proper light:
Is the work close up or is a long-range beam required?
• If your work is close up, LEDs are probably a good choice.
• If long runtimes and bulb life are important, LEDs are probably a good choice.
• If you are looking for a long range and high light output, LED, krypton, halogen or
xenon lights are probably a good choice.
• Is cost of operation and continuous use a concern? If so, a rechargeable light
may be a good choice.
Candlepower (Peak Beam Candlepower)—A measurement of the brightest spot
in the focused beam (usually @ 100 ft.). It is a function of both the output of the lamp
and the efficiency of the reflector. The term “candlepower” (candelas) originates from an
older unit, the candle, and was based on an actual candle of specified dimensions and
Lumens (Total Luminous Output)—A measure of the entire light output of the
flashlight regardless of beam focus. It is almost solely a function of the lamp (bulb). This
measurement is taken in a sphere and regarded as the most accurate of the
Foot-candle (FC)—Density of light that falls on a surface. Equal to one lumen per
Haz ardous Locat ions
General-purpose electrical equipment can cause explosions in certain atmospheres.
Equipment, such as flashlights, used in areas where explosive concentrations of dusts
or vapors may exist must be equipped with specially designed switches, seals and other
safety features. Hazardous (classified) locations might exist in areas such as aircraft
hangars, gasoline stations, paint-finishing locations or agricultural areas such as grain
bins. Firefighters typically use hazardous location-rated equipment also, because they
are going into situations where the atmosphere is an unknown. Flashlights that are
rated for these locations will have the class and division markings along with the third
party approval stamped into the flashlight body. In order to make sure the correct
equipment is used, these environments have been broken down into classes, divisions
and groups to more specifically identify the hazards.
SUMMARY OF CLASS I, II, III HAZARDOUS LOCATIONS
I Gasses, Not normally present in
B. Hydrogen, etc.
Vapors and Normally explosive and an explosive
C. Ether, etc.
Liquids (Art. hazardous. concentration (but may
501) accidentally exist).
Fuels, Solvents, etc.
E. Metal Dusts
F. Carbon Dusts Ignitable quantities of Dust not normally
(Some are dust that is normally or suspended in an ignitable
II Dusts (Art.
conductive* and all may be, in suspension, concentration (but may
are explosive) or conductive dust may accidentally exist). Dust
G. Flour, Starch, be present. layers are present.
Plastic or Chemical
III Fibers and Woodworking, etc. Stored or handled in
Handled or used in
Flyings (Art. (easily ignitable, but storage (exclusive of
503) not likely to be manufacturing).
*Electrically conductive dusts are dusts with a resistivity less than 105 Ohm-centimeter.