Tempgun FAQ

Infrared Thermometer Buying Guide

The Infrared Thermometer ( IRT for short ) allows you to easily 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 accessible will absolutely 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 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 $200. 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 TG-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 TG-1 is 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 TG-412L offers a D:S of 12:1 so at a distance of 12 inches from your target you are reading the temperature of a one inch circle. At 24 inches, a two inch circle and so on. That is a huge difference, about 12 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.

** Ambient temp of 77° F (25° C) and object temp of 59° F (15° C) - 95° F (35° C)