A thermal imager is one of the newest tools in a
fire
fighters arsenal. It consists of a camera like unit
that either is
hand-held or attaches to the users
fire helmet. They are used in
low visibility
situations (such as
fires) to allow fire fighters to
locate
victims, the
fire, and women with
breast
implants.
(Note: Yes, that last part is true. Some of our more,
umm, astute, fire fighters discovered it when we
purchased ours.)
To answer your questions, yes, the difference is
unbelievable. If you have ever wondered what it would be
like to be in a fire, strap about 60 pounds of heavy
clothing to your body, put on a mask (covered with
wax paper) and stumble around on your hands and
knees praying to God that the floor you are on doesn't
collapse. Now, keep the gear on, but take off the wax
paper. Everything is very defined.
The drawback? It is technology, so it stands to
reason that it could fail at any moment. While it is
built to prevent that from happening as much as possible
(see below), it is still a possibility. When you are
operating electronics in temperatures approaching
800 degrees, there is always a chance of failure. That
is why this unit should never be relied upon as the sole
method of searching. It is a tool to assist the
rescue operation, not a nifty toy that you just run
around with and become trapped because it shut off.
Because when it shuts off you see nothing. Nada.
Zip. Zero. And you still have a fire, trapped
people, and all sorts of other fun stuff to deal
with.
We have had our unit for about 8 months now, and have
used it many times. The most common use is in situations
where there is a smell of smoke or something burning
at a residence or commercial structure and we use it
to scan the walls for heat differences. Works like a
charm. It also is used by the Primary Search crew and
the Rapid Intervention Team.
Here is some random facts from the Cairns Web Site (the
manufacturer of our thermal imager www.cairns.com):
Technology
The Camera shall utilize a
Microbolometer detector that processes thermal
radiation in the 8.0 to 14.0 micron range of the
electromagnetic spectrum. Thermal sensitivity of the
system shall be better than 0.07°C (.13°F) with a
nominal dynamic range of -30°C (22°F) to +150°C
(302°F) without the use of an iris or restrictive
aperture.
Image Quality & Representation The Camera shall have a
high resolution (76,800 pixel, 320 columns x 240 rows)
full-motion video image (60 hz NTSC or 50 hz PAL)
without jutter. Image shall be void of black halos,
banding, white-out, blooming or significant
artifacting when viewing hot objects. Colder objects
shall be displayed as black shades. Hotter objects
displayed as white shades. Highly radiant energy
displayed in two stages of yellow and red (for greater
than approx. 480°C / 900°F).
IR Field of View & Focus The Camera IR shall have an
IR field of view of 60° horizontal x 45° vertical (75°
diagonal) that is automatically in focus between 1m
(3.28 feet) and infinity (¥).
Weight & Buoyancy The Camera shall have a 5.75 lbs.
nominal weight w/ battery and thermal management block
installed, for ease of handling. Camera to float in
fresh water.
Extreme Heat & Flame Resistance NFPA1981, Method 3-11.1
to 4-11.1
Pre-condition Camera at 95°C (203°F) for 15 mins. Expose
Camera to 1000°C (1832°F) encompassing flame for 12
sec. Camera must not separate or drip. Camera must not
support flame for more than 2.2 secs.
DURABILITY
The Camera shall operate in conditions that are normal
and expected for fire and emergency services. The
camera shall meet the following durability criteria,
without loss of function:
Vibration Mil-Std-810E, Method 514.3, Cat3, Procedure I
Unrestrained Camera (not in carry case) exposed 25.4 mm
(1 in) high, 5 cycles/sec vibration for 20 minutes
while operating.
Impact/Drop
Drop 1 Camera 6 times, once on each axis, from 1 m (3.28
ft) height onto concrete, while operating.
Water Immersion IP67
Operate Camera immersed in 1m (3.28 ft) of water at 23°C
(73°F) for 1 hour.
Driving Rain Mil-Std-810E, Method 506.3, Procedure I
Operate Camera in driving rain of 64 km/h (40 mph) at
rate of 10cm/h (3.9 in/h).
Altitude/Low Pressure Mil-Std-810E, Method 500.3,
Procedure I
Expose Camera to air pressure equivalent to 2438 m (8000
ft) altitude for 12 hours.
Chemical Resistance
Camera shall be resistant to the following
substances:
And for those of you interested, yes, this technology
probably could have saved the
fire fighters who died
in
Worcester, Mass. However, what would have saved
them more would have been a clear
Chain of Command and
Personnel Accountability System, and them not blindly
running into an
unstable structure without
establishing a clear
plan of action.