measurement of a jacket`s waterproofing

I was wondering how do manufacturers such as burton, bonfire and helly hansen measure the degree of waterproofing of their fabrics? I have two bonfire silver series jackets and I`ve never had water go through them but I started wondering about this issue last week.
Also what do you folks think of the new bonfire stuff thats out for this year? It seems a lot thinner and lighter than the old stuff but I`m sorta weary on recommending it to a friend to buy b/c it just doesn`t quite seem as good as the old stuff.

"... one way labs measure waterproofness is by putting a column of water on top of a piece of the material, and at a certain level measured in milimeters (mm), the water starts to seep through. Using this method, a 2000 mm rating means the water seeps through at the 2000 mm level, so it not as waterproof as fabric that will resist the water up through the 10,000 mm level or higher. Other companies put emphasis on "field testing", and do not quantify the waterproof or breathability...."
Just because something is thinner, doesn`t mean that it is less waterproof or whatnot. The waterproofing/breathability is provided by a membrane that is usually sandwiched between layers of nylon or whatever outer and inner shell jacket makers decide to use. Perhaps this year, they decided to go for less bulk, and made their outer layers thinner, probably a way to cut costs as everyone is doing in the economy. It doesn`t mean the waterproof membrane has changed. If there is a "mm" rating, this is one way to compare waterproofness. Otherwise it`s hard to say.
I haven`t really looked into bonfire much.. i usually buy whatever`s on closeout whenever I need the gear.. I`ve been riding a helly hansen jacket the past two years that I scored for $75 on overstock.com
-Tom

Yes, he`s right about the mm ratings, I`ve seen them on a lot of tags. Just don`t forget that the more waterproof it is, the less breathable, so it will trap your own sweat inside and make you wet. I heard that 10000mm is a good balance, but I got a 5000mm pair of pants because it cost a bit less and I think it should do the job. I think 20000 is definitely overkill. Good luck.