I can't make head or tail of how it's supposed to work. Watched the vids, looked at the info on the site, either the hunter guys don't understand a damn thing about the science behind it or it's a "baffle with BS" situation.
Firstly their EM frequency chart has the "human energy signature" in the mid infra-red region, around 10^-5 m wavelength, so that's heat signature, fair enough, I swallow that. What I don't swallow is that THAT signature spikes much. I also do not swallow the idea that a mesh in fabric can block that signature very effectively.
"Radiation from mammals and the living human body. Mammals at roughly 300 K emit peak radiation at 3 thousand μm K / 300 K = 10 μm, in the far infrared. This is therefore the range of infrared wavelengths that
pit viper snakes and passive IR cameras must sense."
http://en.wikipedia.org/wiki/Wien's_displacement_lawThat means the spacing in the fabric has to be less than 10 micrometers, or 0.01 millimeters... looks like it's not gonna be better than a tenth of a millimeter.
I also could accept that the eye could work as a black body absorber and tend to feel a nearby heat source slightly even if you don't really "see" it. So if this was an IR shield there might be some value to it BUT... after wearing it for a while it would heat up close to your body temperature, so would then still emit IR in the 10 micrometer band.
But if it worked for this they would be able to walk in front of a "passive IR sensor" right? Well, yes and no, if the surface of the material remained at ambient temperature, so representing no difference to the background, then the sensor would not register a change. But it might block stable heat sources that are part of it's background, or might reflect heat sources behind it, so registering a change...
So is that why they used a "microwave" activated light for one of their videos? That one is a huge puzzle, because those type of lights DO NOT work on any passively emitted energy, they use the doppler effect to detect movement. They are actively emitting microwaves and if anything gets reflected back with the frequency skewed, then an object moved. However, a simple mesh suit should be a relitively HUGE radar target. Which would be like trying to hide from a searchlight by holding up a mirror. So what's going on? Well either this is a true stealth fabric, in that it's a radio emission absorber, which is very difficult to achieve on a hard surface nevermind a flaxible one, or they just got lucky with the frequency of that unit, which could be close to the mesh spacing in the fabric, which would give it some stealth properties for that frequency only... and bear in mind this merely reduces radar cross section, there should still be some return off any surfaces perpendicular to the beam... though the unit could have been tuned to be insensitive to something bird or squirrel sized.
So if the thermal IR suppression theory is BS what about the "tri-field" meter test?
Well the emissions this detects should be much longer wave radiation than IR I beleive these units have a maximum detection frequency of something like 2.5Ghz, which if my brain is caffeinated enough this morning means about 12cm wavelength, should be able to block that with "chicken wire". There are very weak emissions at frequencies lower than this from the human body. I have a field strength meter here that has a sensitivity of up to 1 milliwatt per cm squared and I can just about make it twitch moving my arm over it, but put the coil in the region of my heart and I get a reading of 0.2mW/cm^2 when I'm sitting down, and walking around 0.3-0.4, so when heart rate picks up emissions double! (One of my cats reads about .2 in the heart region also) So it's entirely plausible that your emissions increase when you get excited, or start doing something strenuous, like hauling back a bowstring and holding it taught. Since this is a longer wave emission though I highly doubt the eyes have anything at all to do with detecting it, it would need a long "antenna" like maybe the nerves of the spinal cord, which might explain the "shiver in your spine" type feeling... but this must be rather short range, since the emission is very weak and decreases by the square of the distance.
(Also getting an itch in my brain that there's something to do with polarisation that could mean a critter with a horizontal antenna (spine) probably picks up a critter with a vertical antenna very easily and vice versa, but can't remember it well enough to explain)
Not sure I beleive the claimed 40m thing mentioned in the vids, since I've twice been as close as 5m to white tail before they spooked, and got within 20m of some yesterday... wasn't hunting them though.
Flash