IRR?

#1
Hi there,
I've been wondering if someone can explain this concept a bit. I've heard that most non-issue items are not IRR, and therefore appear to glow when seen through night vision equipment.

I've also heard that comercial detergent makes IRR items non-IRR (though from my own experience I don't believe this). From what I've seen, it appears to be mostly synthetic materials which have this problem as I've seen waterproofs and fleece tops which appear very bright through NVGs.

The concept of things being Infra Red Reflective, would in my opinion make them appear brighter (i.e. reflecting light). So why is it that non-IRR things don't appear dark through NVGs?
 
#2
Tartan_Terrier said:
The concept of things being Infra Red Reflective, would in my opinion make them appear brighter (i.e. reflecting light). So why is it that non-IRR things don't appear dark through NVGs?
The reason you can still see IRR treated (issue) items theough NVGs is that the NVGs enhance available light sources and utilise IR light as available. So the image you are seeing of issue kit is that of ambiant light and a lower level of IR reflection than non treated kit.

If you look at things like softie jackets or wooly hats with NVG kit and an IR source they will appear bright white.

(i think)
 
#3
I assume you're referring to near-IR systems (through which we perceive the world as being 'green' - due to the phosphourus in the phototube) as opposed to far-IR - or TI.

Through a TI EO device, a non-radiating body (or someone wearing a highly effective thermal cover) will appear effectively 'invisible'. Near-IR systems work by reflecting ambient light (as admirably explained above), so the only way your men would appear 'black' would be if they were wearing light absorbtive clothing - in effect, stealth uniform, as it would be absorbing the wavelengths of light.

Edited to add: The terms 'near' and 'far' IR are broadly relative to 1-2 microns for near IR II systems; and 3-5 and 8-14 for far TI systems.
 
#4
Back in the 80,s I remember someone saying that you wern,t allowed to wash your combats yourself due to IRR becomeing ineffective. You was supposed to hand them into the QM,s for special cleaning & treatment. Yeah right !!! when we were on exersise for 6 months of the year during the BAOR days a 3 to 4 week wait for combats was,nt that practical. I don,t think anybody actually went through that route.

Regards LT.
 
#5
That's absolutely correct.

You shouldn't wash CS95 at all, and certainly not use starch or other solvents on them.

Going off-topic for 2 ticks, you also aren't supposed to 'bull' CAB either...or sew badges all over your kit.
 
#6
It's some years since I did the STANOC course (is it even called that any more?) but, as I remember it, the IRR problem was to do with active IR illumination systems used with IR goggles - which are pretty much obsolete these days and have been since image intensifiers came in, never mind TI. Anyway, apparently there is a big difference in the degree of IR reflectivity of urban and rural backgrounds, with rural being much higher. The idea of IRR clothing was to mimic the reflectivity of the most likely operational background - which, at the time was, again, if I remember correctly, the rural one.

I don't think IRR really has any relevance to detection by more modern methods, except that I know an IR light source is very easily detected with an image intensifier, so I guess that a highly IR reflective thing would be quite easy to see against a low IR reflective background, if there were much in the way of IR light about. That ought to mean that IRR kit would not be the thing to wear in an urban environment - supposing I haven't got the whole thing the wrong way round, which is quite likely.
 
#7
Since on one patrol we had to wear ir lightsticks so our snipers wouldnt shoot us .(Not sure what system they had that could hit
in a pitch black rainy night 2km away but not willingy to experiment ) Is irr really an issuse nowadays :?: .
And yes someone did say my lightstick dosen't seem to work :lol:
 
#8
Commercial washing detergents generally use a chemical that glows in UV light, you won't notice it until you mix some powder and water and look at it in the dark with a UV light, it then glows like a barsteward! It's there to make your "whites whiter" hence it's not idea for washing your combats!

I believe soap flakes are free of it and a suitable alternative, although don't sue me if you get shot because I only said "I believe", it ain't gospel.
 
#10
Through NVGs my Pikeytex daysack sticks out like a bulldog's wotsits, while my issue kit remains dark. Though I think ingrained dirt is fairly effective at reducing IR reflection, so the less you wash your kit the better. Obviously I'm only talking about webbing.
 
#11
Thanks for the info guys.

Just for the record it was image intensifiers I meant, as unfortunately thermal imagers are as yet not issued to my unit.....could be nice though!
 
#12
Darth_Doctrinus said:
You shouldn't wash CS95 at all, and certainly not use starch or other solvents on them.

quote]

So if we *do* have to wash them (eg they're absolutely after a weekend in the field and the Tp Cpl insists they're cleaned and ironed next time you're on duty) what's the best way of doing this? Presumably without any conditioner?
 
#13
ssupersixfour said:
Darth_Doctrinus said:
You shouldn't wash CS95 at all, and certainly not use starch or other solvents on them.

quote]

So if we *do* have to wash them (eg they're absolutely after a weekend in the field and the Tp Cpl insists they're cleaned and ironed next time you're on duty) what's the best way of doing this? Presumably without any conditioner?

Im not quite sure about the conditioner and obviously we do have to wash our kit, i dont know if this is true but i heard somewhere that when you send your kit to be cleaned through the army dhobi system it gets re- treated with an IRR agent and a water repellant . If its true it might be a good idea to put your kit into the SQMS/CQMS once in a while to make sure that it retains its IRR properties.
 
#14
I dont know about special treatments but the dhobi in Kosovo used to add a nice diesel fragrance to all my washing....including me shreddies. They always seemed dirtier than when I put them in.
 
#15
Someone mention phosphourus?

Darth, since you seem to know, does ironing CS95 affect its IRR properties, or is it just the starch?
 
#16
Northern_Biff said:
I dont know about special treatments but the dhobi in Kosovo used to add a nice diesel fragrance to all my washing....including me shreddies. They always seemed dirtier than when I put them in.
I remember that the Mobile Bath and laundry units in bosnia were shite. The ecolog that are being used in iraq at the moment are quite good apart from the fact that you are lucky if you get your shreddies back. They do a nice colour though i think its called army boilwash grey.

I should have been a bit clearer, i meant the dhobi system when you are back in camp in the UK or Germany.
 
#17
Had a powerpoint presentation somewhere along the line about cam and concealment and the guy that did it had a couple of neat slides showing the effects of ironing CS95. Where Trooper Snodgrass had lovingly put razor creases into his kit, they showed up as bright lines and created a sort of 'stick-man' effect. I was led to believe that ironing was much more of a problem than washing, as the IRR properties are in the dyes and not a surface treatment.

TM
 
#20
I was told on my STANOC course (by some impressively scruffy folks) that even ironing damages it - and this was proven to be the case on numerous exercises, using a range of rather gucci II systems. It has something to do with heating and re-heating the fibres.

Starch is even more damaging, but does anyone use that sh!t anymore? I hope not...

Incidentally, I always chuckle when I hear bolshie SNCO types telling impressionable young soldiers that the new kit can be ironed/starched etc, and all this talk is nonsense. Of course it is, chaps - our procurement system has a long and glorious history of delivering kit that pleases everyone, after all.
 

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