Nope ... my point was that the Pertex brand name "Quantum" is used by garment manufacturers for fabrics that have VERY DIFFERENT CFM values. You either have to test each version of what a garment manufacturer is calling Quantum (ideal) or call/Web browse the manufacturer and get the specs for the version used in the garment of question (problematic). I called TNF yesterday and they said that the version of Quantum that they are using in the 2011 North Face Verto Jacket is 7 CFM.
Martin reported in this forum thread relative to Montane’s current Web specifications, “They do actually give comparative test results for quantum and microlight (used on various of their windshirts) which seem identical cf air permeability: 1.0cc max (JIS L 1096 / ASTM D737).” The ASTM D737 standard on page 3 says, "11.1 Air Permeability, Individual Specimens—Calculate the air permeability of individual specimens using values read directly from the test instrument in SI units as cm3/s/cm2 and in inch-pound units as ft3/min/ft2, rounded to three significant digits." So although Montane is not following the standard regarding how they represent their results, we can logically assume they mean cm3/s/cm2.
Alternatively we can take the 7CFM rating provided by TNF and convert it to cubic centimeters per square centimeter of sample per second, which is what I think Montane means with their abreviation cc. TNF converted to Montane format would be 3.556cc. Montane says Microlight is the same and yet I measured it 15.59 CFM or 7.9cc. To interpret windshirt specs requires complex conversions and after the conversions the results between different windshirts using the same material are different.
This is why I said just going on specs is problematic. Furthermore if you try and find out what the CFM rating are for any wind shirt sold in the US it is nearly impossible. Other than for Outdoor Research’s Cirque Windshirt, this information is not provided. What is left is decision making along the lines of “That one is lighter and so it is OBVIOUSLY better”.
My Montane Lite Speed measurements, were 100.62 CFM (51.11cc) for what they called Quantum and 15.59 CFM (7.92cc) for what they called Microlight. I measured these values using my Gurley 4100N Densometer-Porosity-Permeability tester. This instrument is a piece of precision test equipment. It is consistently rated as one of the best in the world for measuring air permeability of a material. For grins do a search on the US patent data base and you will find this instrument is what Gore and most other large companies use to qualify air permeability measurements in their patent claims. The Frazier instrument is the other instrument commonly cited in patents. It is more accurate on high CFM items like fleece and mosquito nets.
I haven't tested the North Face Verto CFM claim but if I tested a jacket that measured 7 CFM air permeability, I would rate it as highly "wind resistant". The industry norm for a "windproof" classification is 0 - 5 CFM. That said, most BPL forum highly rated wind shirts are only "wind resistant" and have CFM ratings significantly higher than 7 CFM.
Air permeability (CFM) is more closely correlated with thermal comfort than is MVTR. The issue with UL backpacking is the variable high MET rates generated during inclines with a pack. The sweet spot between wind resistance and overheating for most UL backpackers is in the 40 CFM range. You need a CFM rating of approximately 400 to never have a wind shirt cause you to limit your MET rate. 400 CFM is what I measure on the typical light cotton T-shirt.