Windshield Glass Reflections - How to Remove Them

by Bernie Lyon, Gary Orlove, and Jason Gagnon

"I do a lot of windshield defrost testing at different temps. And I wonder is there any way that can keep from having the camera and myself reflected back into the images."

Glass is about 15% reflective in the 8-12 micrometer waveband. If you are directly facing the windshield, you will inevitably get a reflection of yourself and the camera. I'm sure you have seen this.

One option is to change the angle at which you are observing the windshield, see the image below. If you are at point A, you and the camera will be reflected. If you are at point B, the camera will reflect whatever is above the vehicle, represented by C.

If there are hot objects or objects with temperature variations above the vehicle, that might make things worse. They will reflect off of the glass. If possible, you could place a high emissivity piece of material above the windshield so that all reflections off of the glass are uniform. A large piece of cardboard or a blanket might do well.

This way, you will observe only temperature changes, not patterns due to non-uniform reflections.

Another option is to use image subtraction techniques (you will have to have software which supports this, such as FLIR ThermaCAM Researcher).

1. Take an image before running the defroster.
2. Then save images as you normally would.
3. Subtract the first image from the succeeding ones. The resulting image will show only changes in temperature and the reflections will have been eliminated. See the series of images below:

Ghost in the…Refractory?

With Halloween coming up in a few weeks, we’ve got a fun “ghost hunter” video that we’re putting the final touches on which I think you’ll enjoy.  Keep an eye out for it right before the end of the month. Until then, on a related note, a thermographer from a recent ITC training course sent in this gem of a find.

ITC Instructor John Waggoner received these images from Craig Dickey.  Craig was conducting a furnace inspection at the time when he came across this unusual thermal pattern while scanning around the access door.  I guess IR really CAN be used to find ghosts or, in this case, perhaps some type of thermal spirit of refractory inspections past?

It got me thinking, have any of you found similar? Perhaps an interesting IR pattern that caught you by surprise, maybe something that wasn’t obvious visually, but jumped right out at you thermally? Share it on our Facebook page and I’ll post it to the InformIR blog as well with a photo credit.

Infrared Everywhere: Hot Chicks

After I joined the ITC team this past fall, my family and I have been caught up in the process of relocating to southern New Hampshire. Now that we’re finally settled in, and the last of the moving boxes have been emptied, I guess it was time to take on another challenge, this one involving fresh eggs. My wife has always wanted to try raising chickens, and now that we live on a small farm, what better place to take the plunge!

The little ladies arrived in the mail about five weeks ago (yes, the Post Office delivers chicks) and have been growing rapidly ever since. Here’s a quick infrared video from their first week inside the house, captured with a FLIR T650 thermal imager:

IR Cost Savings for Seam Welder PM’s

by Steven Noel
Reliability Engineer / Group Leader
Batesville Casket Co.

The Batesville Casket Assembly Plant located in Batesville, Indiana has two Seam Welders in their fabrication department. These Seam Welders are resistance welders that are designed to weld a continuous weld that holds the casket bottoms in place while making an air tight seal. Each Seam Welder runs proximity 27 units each hour and is in use for up to 10 hours each day throughout the week.

When a seam welder starts failing due to insulation failure you start seeing poor welds which in some cases don’t show up until the unit is built and vacuum tested prior to ship out. At this point to make repairs to the casket is costly due to disassembly and removal of the interior to gain access to the bottom.

Furthermore if one of the Seam Welders were to fail during production it would reduce production by 50%. The lead time for making this type of repair is two to three hours causing production losses estimated at eight to ten thousand dollars.

These Seam Welders are 16 volt DC / 20,000 amp resistance welders so being very low voltage and high amperage any insulation breakdown will cause the foot and lower wheel to overheat and eventually fail.

Black Ice Thermal Images

Please see thermal images and associated visual images of black ice below:

Analyzing Building Images Acquired at Different Times

A camera user writes:

"I find that images taken of the same structure, not much separated in time, sometimes look very different.  This poses a problem for me as I’m trying to compare the heat images of different houses (to detect homes that need weatherization).  Presently I’m not confident that images of two homes reflect actual differences in the structures, or are caused by minor environmental changes or even by artifacts in the photography.  Here is an example.

Attached are two nighttime images of the front of my house, which faces east.  IR0310 was taken at 10:40 PM, IR0408 at 11:11 PM. (The clock on the camera is two hours fast.)  It was a cold night with little temperature change over the half hour between pictures.  The house thermostat was constant. 

I've set the palette and temperature range to give me good differentiation of houses along the street.  I took the first image of my house as I began imaging houses on my street, and I took the second image when I finished the street scan. 

I am surprised, first, that my house looks so different in the two images. And second, that the outside looks warmer in the later image.  If anything, I'd have expected the outside to have cooled.

Glad for any interpretation of this.  Needless to say, with this kind of variation on a single house, it is hard to get good images for comparing houses. "

Live IR Imaging of Iceland Volcano

A FLIR A320 infrared camera was shipped to the Icelandic Mila company and is now installed to monitor Eyjafjallajökull volcano. The camera is installed approx. 10 kilometers away.

View live visible and infrared imagery of the volcano at the link below.

LIVE VOLCANO IR VIDEO