Argon-Testing Procedure

Testing for argon gas content was performed on all of the small testing units at four specific time frames, (initial, after 2 weeks in high-humidity exposure, after 9 weeks of weather cycling, and then again after 4 more weeks of high-humidity exposure). Units were tested by non-destructive spark emission spectrography in accordance with ASTM E2649 [15]. For an IGU to be listed as complying with gas content certification, the unit must demonstrate an average argon contain­ment of greater than 90 % before weathering, and the average argon levels of the entire sample group must be greater than 80 % after weathering.