Infrared Thermometer Buying
Guide
The Infrared Thermometer
( IRT for short ) allows you to very precisely monitor the temperatures
in an unlimited number of areas in no time at all. The IRT is
not dependent on a sensing probe to take the temperature of
surfaces but rather uses infrared technology to determine the
temperature of about any surface with remarkable accuracy and
speed. Typically a temperature can be taken in a matter of a
couple of seconds and the push of a button. Think of all the
time and money that can be saved on purchasing, placing and
monitoring several digital thermometers. Having this knowledge
at your fingertips and readily accesible will absolutley improve
your ability to keep and breed the animals you love. There is
simply no substitute! The following information is designed
to help the new and seasoned user alike get the most accuracy
and value out of the IRT they purchase. Buy it once and buy
it right!
By far the number one question
we are asked regarding the purchase of IRT's, or Tempguns, is
"Which one of these do I need?? I have no idea what these
specifications mean to me!!"
First is the accuracy of
the reading. When
selecting the best IRT for your needs the accuracy of the various
models is pretty much unimportant, they are all about the same-
+/- 1° Celcius (See Figure 1) regardless
of the make, model or cost.
Second is the emissivity.
To
all but the most advanced user the emissivity is best left alone
and is properly set at the factory at .95.
Many of the models available have an adjustable emissivity should
you ever need to change it.
Third is the IRT's measurement
range. Unless
you have a very specific application outside of the reptile
hobby almost any of the IRT's available will be more than up
to the task. See
Figure 1
Laser
aiming is provided on all but the most basic models. While sometimes
helpful for aiming your IRT over longer distances you should
understand that the laser itself has NO part of the actual temperature
reading. The laser's sole
purpose is as an aid in aiming.
Some high end models, such as the RBI
425L use multiple lasers to help the user better pinpoint the
field of view of the tempgun.
None of the IRT's will read
through glass or plastic cage fronts. Essentially, they read
the surface closest to them. What you see first is what you
get.
Now that we know what is
common among nearly all of the IRT models, lets look at what
you are actually paying for. The first thing driving price is
pretty obvious-the quality of the unit you are purchasing. This
can range from a $10 plastic novelty/toy up to a several hundred
dollar high-tech scientific instrument. If you look at the IRT
products we offer here at RBI you will see a price range of
roughly $25 to $160. We have carefully selected among several
hundred available IRT's to find the best value available for
the money. Cheap is nice but it is not better! Once you have
used a higher quality gun, like our 412L you will not want to
go back entry level models. In fact, we have found several of
the models we have tested and sell actually outperform their
specifications in our facility! All of the IRT products we sell
carry a one year manufacturers warranty and if cared for should
provide a lifetime of reliable service.
Now for the real difference
among the high quality IRT's prices-The D:S ratio. Distance
to Spot ratio is just about the most important aspect of proper
IRT selection. It tells you how large of an area you are taking
the temperature of when you use your IRT. Like photography equipment,
good optics just don't come cheap. For instance, the PE-1 or RBI 201 model
is a very basic and offers a D:S of 1:1. That means at
one inch from your intended target you are taking the reading
of a one inch circle. At four inches a four inch circle and
at six inches a six inch cicle and so on. The RBI 420L offers
a D:S of 20:1 so at a distance of twenty inches from your target
you are reading the temperature of a one inch circle. At forty
inches, a two inch circle and so on. That is a huge difference,
about 20 times a tighter spot than the 1:1 models.
We recommend you select an IRT that will keep your temperature
reading area at or below a four inch circle at your typical
distance from your target. If you look at Figure
2 ( below) you will see the effective ranges that you can
maintain this four inch circle with each of the various models
we offer. You may also want to
think about your needs in the future as well. Hopefully you
will only be purchasing your IRT once and using it for a very
long time! Spend your money wisely and get the right tool for
the job the first time, you will be glad you did.
Figure
1-Specifications |
MODEL |
ACCURACY |
TEMP.
RANGE |
D:S |
|
+/-
1° C** |
-27
to 428 F or -33 to 220 C |
1:1 |
|
|
-67 to 428 F or -55 to
220 C
|
1:1 |
|
+/-
1° C** |
-67
to 482 F or -55 to 250 C |
6:1 |
|
+/-
2% or 2° C, Whichever is greater |
0 to
750 F or -18 to 400 C |
8:1 |
|
+/-
1° C** |
-76
to 932 F or -60 to 500 C |
12:1 |
|
+/-
1° C** |
-76
to 1400 F or -60 to 760 C |
20:1 |
RBI
425L |
+/-
1° C** |
- 76 to 1832 F or -60 to
1000 C |
50:1 |
** Ambient temp of 77° F (25° C) and object
temp of 59° F (15° C) - 95° F (35° C)
Figure
2-Effective Distance |
MODEL |
D:S |
Max.
Distance w/ 4" SPOT |
NOTES |
RBI
201 |
|
Keep target within 4"
for best results
|
Useful
for the majority of reptile applications, an exceptional
value for close range work
|
RBI
205L |
6:1 |
Keep
target within 24" for best results |
Inexpensive
upgrade from the PE-1. Laser aiming and greater distance
capability. Best value for intermediate hobbyists |
Raytek
MT4 |
8:1 |
Keep
target within 32" for best results |
Nice
upgrade for the intermediate hobbyist. Laser aiming. The
smallest D:S we would consider for venomous/hostile animal
use |
RBI
412L |
12:1 |
Keep
target within 48" for best results |
Good
for intermediate/advanced hobbyists. High quality. Laser
aiming. Well suited for stores/small institutions. RBI
420L would be recomended for venomous/hostile animal
needs. Best value in the intermediate class
|
RBI
420L |
20:1 |
Keep
target within 80" (6.5 ft) for best results |
Advanced
users/hobbyists. Recomended for mid sized venomous/hostile
animals. Great value for small institutions, HVAC, and
small to mid sized venomous/hostile animals |
RBI
425L |
50:1 |
Keep
target within 200" (16.5 ft) for best results |
Advanced
users/hobbyists. Recomended for mid sized venomous/hostile
animals. Best choice for Institutions/Zoos, HVAC, and
venomous/hostile animals |
