Message Board Thread - "Automotive Glass"

Title	By	Posted On
Automotive Glass	Integrator500	10/11/2006
Can a thermal camera pick up heat when aimed through automotive glass? Can reflectance create issues? Does window tinting affect performance?
Re:Automotive Glass	jvoitl	10/12/2006
Glass is not transparent for IR. All you'll see is the temperature of the glass itself.
Re:Automotive Glass	Gary Orlove	10/12/2006
Many glasses are quite transmissive at wavelengths below 4 µm. So a properly filtered Midwave IR system can see through the glass. At wavelengths longer than about 4.5 µm, the glass becomes opaque so an IR system filtered in these regions would not be able to see through the glass but instead would "measure" the thermal emission from the glass. Gary Orlove Infrared Training Center
Re:Automotive Glass	RLDavis	11/7/2006
I am having trouble locating the images, but I had an example that may shed some light on your question. I was doing an evening survey, checking out my house for thermal leaks. The temperature was about 22 degrees F, and I took a look at my Chevy Tahoe. In the rear window, I had some really pretty thermal reflections of the trees. When I looked at the front window, I had actual temperature measurements of the window, and you could see the pattern of the defroster as it blows on the window from the inside. It appears that if the temperature of the glass is lower than the items being reflected, the trees in this instance, then you only see the reflections. When the temperature of the glass, and the thermal energy given off by the window, exceeded the reflected temperatures, I no longer had reflections, but actual temperatures of the surface of the glass. If I locate the images, I will upload them. Ron
Re:Automotive Glass	DonW	11/7/2006
During one of the Information sessions a report was given on how an IR camera was used during the design stage to detect the pattern of the defrost vents on a car's windshield. The IR camera, positioned on the outside of the car, could NOT see through the glass but could measure the surface temperature of the glass. The defrost vents were positioned to give the best distribution of heat to the windshield.