Reproducibility of He, Ne, Ar, Xe on air aliquots over a 3 day period
20Ne =1.6 x 10-10 cc STP; reproducibility of ratio = 0.7 o/oo
36Ar = 3.3 x 10-11 cc STP; reproducibility of ratio = 2 o/oo
130Xe = 3.5 x 10-14 cc STP; reproducibility of ratio = 8 o/oo
reproducibility of ratio = 4.5 o/oo
