As many of you know or have seen, we at SLS Construction are now offering Residential, Commercial, & Industrial Infrared Thermographic Inspections throughout Alabama. This has led to a few questions that we thought we would try to answer all in one place.
In layman’s terms, what is Infrared Thermography?
It is utilizing technology to see how hot or cold an item or area is and the transmission of heat.
What is Infrared (IR)?
IR stands for Infrared Radiation, which is part of the electromagnetic spectrum. It is invisible to the human eye because its wavelength in the spectrum is too long for the sensors in our eyes to detect it. While our eyes may not see it, we can still sense it through feel; how hot or cold an item is. Unlike visible light, in the infrared spectrum, everything emits an infrared electromagnetic energy depending on its temperature. The hotter the object is, the greater the infrared radiation is emitted.
Can you refresh my memory on the electromagnetic spectrum?
electromagnetic spectrum
Courtesy of the University of Iowa (sometimes a picture is better than a thousand words)
If you cannot visibly see Infrared, how do you see it?
First, let us take a quick look at the electromagnetic spectrum above. Except for the visible light portion of the spectrum, you can’t see radio waves, or X-Rays can you? However, you can see the result of your X-Rays at the doctor’s office, or turn on the radio to listen to the radio waves, correct? The same is true of Infrared; we utilize special detectors on our cameras to capture a picture of the Infrared Radiation being emitted.
How new is this technology?
Sir William Herschel first discovered the Infrared spectrum, back in 1800. By 1917, Infrared was being utilized on the Battlefield by the British. In the 1950’s thermal images were being produced. In 1952, the heat seeking Sidewinder missile was created. In 1965, the technology became commercially available. Since that time, there have been numerous advancements in not only the equipment, but also a better understanding of its uses.
Sounds great, can you see through walls with it like they do in the movies?
Sorry folks, that is still science fiction – infrared camera’s can only be used to scan the surface of an item or area.
So what can it be used for?
The possibilities here are almost endless, in the residential arena we use it to spot where water leaks are, area’s where moisture is or was in the building structure, missing insulation, air leaks, etc… In the industrial and commercial environment, almost everything gets hotter or cooler before it fails. In many cases if you have two or more similar items running side by side, you can easily spot an issue with one of them because it does not match up with the other. In today’s marketplace, industries are continually striving to improve their manufacturing efficiencies, lower their energy costs, improve product quality, and enhance worker safety, resulting in new applications being developed almost daily. One of the funniest I heard about was a farmer looking to find which female cows were in heat, so he could get them mated. Well since a cow in heat, is actually a few degrees warmer, he drives by them while they are feeding to find out which ones are ready.
Is there anything that it cannot be used for?
Just like any other testing, infrared thermography does have its limitations. Just like visible light, infrared radiation travels through space at the speed of light and can be reflected, refracted, absorbed, and emitted. While the absorption and emitting are great items, some items cannot be readily scanned because of how reflective a surface is or it has a low emissivity. For example, trying to find air leakage in a metal duct system would probably be better off being done utilizing another form of testing.
Can anyone do this?
In all honesty, taking thermal images is quite easy these days. All you have to do is push the auto button and there is an image. The real work, and value of hiring a company like ours is our understanding of the physics behind it and being able to spot what is real and what isn’t. Is that picture taken on auto the best it can be, or would a skilled individual that knows how to adjust the camera to enhance the thermal details be better. Do they know how to evaluate the image once it is stored and downloaded onto the computer? Can they prepare a report that is not only accurate, but also easily understandable by the end user that may not understand what those funny photos represent? Just like most items in life, and especially in the nondestructive testing fields, the interpretation of the information gathered takes both education and experience.
Photo 1 – IR images can be decieving, if one does not know what they are looking at. While the area’s around the window and top plate need to be properly air sealed, the bulk of the high heat shown at the soffit area, is actual heat escaping from the fiberglass insulation on a modular home.
Photo 2 – great shot I took of a ceiling fan, showing how the heat radiates and warms the other surfaces, utilizing Fluke’s software to adjust the IR & Visual visibiality
Photo’s 3 & 4 – same shot, diffrent editing technique – taken in the middle of the night of some goat’s about 75 yards away (a little past this camera’s range to get perfect focus).
Photo 5 – The Electromagnetic Spectram once again… (Ok, I can’t see how to remove it from the gallery & still have it show properly up top – sorry)
Hopefully this answered most of your questions, if not please feel free to shoot us an email or post a comment below.
