I call "staged". When dealing with IR cameras (including FLIR models), you need to be aware of a number of variables, including the emissivity of the object and the emissivity and transmissivity of the air (and whatever else sits between you and whatever you're looking at.).
Gasses have a very, very low emissivity, while solid objects (and most especially darkly-colored objects...google for "blackbody radiation") have much higher objects. What this means is that the actual IR radiation you receive is not directly related to the temperature of what you're observing. As an example, I've used FLIR cameras to observe the flame of a butane lighter, with the camera tuned for observing my working environment. The butane lighter's flame only showed about 130F, which is much, much lower than what the actual temperature of those gasses was. If I'd tuned the camera for observation of gasses, I might have gotten closer to seeing the actual temperature of the butane lighter's flame, but the information would have been largely obscured by the fact that all the solid objects in the room were emitting massively more IR radiation, which would have likely made the rest of the room read as though it were over a thousand degrees Fahrenheit, when the room was actually only about 80 degrees.
That man's internal temperature (which is going to be the temperature his gasses escape at) is going to be around 95-98 degrees Fahrenheit. The first layer of clothing is going to be closer to environment temperature, and any additional layers on top of that are going to be closer, still. Indeed, if you look at that animation, you can see that he's wearing a heavy winter jacket.
His ambient temperature isn't very close to that of the room, suggesting he hasn't been in that cold of an environment for very long. This is backed up by the fact that you can see he isn't wearing gloves, and his hands are quite warm. (At the very least, they're not cold enough to cause discomfort yet, or he'd be doing something about it.)
My first guess was that they put some kind of powder on his pants, and it's the powder that you're seeing the IR emission from. However, looking at all the things I mentioned in the previous paragraph, I suspect that he was indoors, and just walked out into a very, very cold environment, with the camera either already set for an appropriate display range, or with the auto-ranging visual mode enabled. Powder may still have been involved, though; Otherwise, that room emvironment have to be incredibly cold, on the order of thirty or forty Fahrenheit below zero.
Yeah, I just spent half an hour deconstructing a fart joke. I couldn't help it; My day job is writing software that uses these cameras...
That's from the episode of SNL that Hugh Laurie hosted. They were doing a parody of those ghost hunter shows on the Travel Channel. Notice the icons for the Travel Channel AND NBC on the bottom of the screen.
I call "staged". When dealing with IR cameras (including FLIR models), you need to be aware of a number of variables, including the emissivity of the object and the emissivity and transmissivity of the air (and whatever else sits between you and whatever you're looking at.).
ReplyDeleteGasses have a very, very low emissivity, while solid objects (and most especially darkly-colored objects...google for "blackbody radiation") have much higher objects. What this means is that the actual IR radiation you receive is not directly related to the temperature of what you're observing. As an example, I've used FLIR cameras to observe the flame of a butane lighter, with the camera tuned for observing my working environment. The butane lighter's flame only showed about 130F, which is much, much lower than what the actual temperature of those gasses was. If I'd tuned the camera for observation of gasses, I might have gotten closer to seeing the actual temperature of the butane lighter's flame, but the information would have been largely obscured by the fact that all the solid objects in the room were emitting massively more IR radiation, which would have likely made the rest of the room read as though it were over a thousand degrees Fahrenheit, when the room was actually only about 80 degrees.
That man's internal temperature (which is going to be the temperature his gasses escape at) is going to be around 95-98 degrees Fahrenheit. The first layer of clothing is going to be closer to environment temperature, and any additional layers on top of that are going to be closer, still. Indeed, if you look at that animation, you can see that he's wearing a heavy winter jacket.
His ambient temperature isn't very close to that of the room, suggesting he hasn't been in that cold of an environment for very long. This is backed up by the fact that you can see he isn't wearing gloves, and his hands are quite warm. (At the very least, they're not cold enough to cause discomfort yet, or he'd be doing something about it.)
My first guess was that they put some kind of powder on his pants, and it's the powder that you're seeing the IR emission from. However, looking at all the things I mentioned in the previous paragraph, I suspect that he was indoors, and just walked out into a very, very cold environment, with the camera either already set for an appropriate display range, or with the auto-ranging visual mode enabled. Powder may still have been involved, though; Otherwise, that room emvironment have to be incredibly cold, on the order of thirty or forty Fahrenheit below zero.
Yeah, I just spent half an hour deconstructing a fart joke. I couldn't help it; My day job is writing software that uses these cameras...
Dude that is way more info than I was expecting to get from the comments, but it still kind of interesting. Thanks :)
ReplyDeleteThat's from the episode of SNL that Hugh Laurie hosted. They were doing a parody of those ghost hunter shows on the Travel Channel. Notice the icons for the Travel Channel AND NBC on the bottom of the screen.
ReplyDelete