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Old February 28th, 2011, 04:51   #31
L473ncy
 
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Join Date: Oct 2004
Location: 11-30-24-1W5
If you're wondering: EN 167:2001 is the directive for the test methods for the EU while EN166 is the marking standards and nomenclature. I can't seem to find EN167 though (well I did but the website wants like 70 quid for it.....).

I know with the ANSI Z87.1-2003 standard it's tested by "shooting" 1/4" steel balls at the lenses at various velocities (I assume that's diameter here, so I get approx .1341 cm^3 for volume).

Taking the velocity and weight of a steel ball (assume 100% pure steel) the density is about 7.8 g/cm3 so about 1.05g for a 1/4" steel ball.

So doing the math for the joule conversion of that steel ball being shot at 250 ft/s it comes out to roughly 3.03J. Definitely less than the energies that we see in Canada. At 500 FPS with .20's you're only sitting at 2.31J, and most of the time it'll be under 420 FPS or 1.63J.

Anyways, if the EU test is done by shooting a 6mm steel ball at the glasses (going with the test method you've posted in this thread) then 6mm is slightly under 1/4" (.236 inches to be exact). Don't fret that it's a smaller/lighter projectile you still need to factor in speed. At 120m/s you're looking at 394 FPS according to my calculations. So by my calculations a .86g 6mm steel ball flying at 394 FPS will exert 6.17J of energy. For your goggles to survive a 6.17J strike you're totally good since the ANSI standard is only surviving a 3.03J strike.

NOTE HOWEVER THAT THIS DOES NOT MEAN YOU CAN PLAY WITH THOSE GOGGLES AT A PAINTBALL FIELD YOU MUST USE ASTM (OR SIMILARILY RATED) GOGGLES/MASK IN ACCORDANCE WITH THE LOCAL SITE RULES!

As you know insurance companies are looking for any way to not pay out and if it's established that players were not wearing ASTM rated PB goggles (in fact these are rated to 11Joules so I'm told) then that's enough proof that they don't need to pay since the field owner did not follow the insurance stipulations to the letter. Even if players were wearing MIL standard goggles that can stop a .22 at 550 FPS (and that's way more than 11Joules if you do the math) the insurance company will still argue that it doesn't need to pay out.

PS: If I've started to spell things with an "s" instead of a "z" or use the words chips (for fries), flat, quid, nutter or any of those words... yeah it's probably because I've been here for close to 7 months now.

EDIT: The only thing you need to worry about is the Bioval BBBMAX "CLEAR" BB's (silica). The standard opaque/Biodegradable ones AFAIK are good to go just like any other standard airsoft BB.
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Last edited by L473ncy; February 28th, 2011 at 04:53..
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