nitrogen helium
TN2(min) a + 33/b (f sw)   1/b THe(min) a + 33/b (f sw) 1/b
4.0 106.2 1.91 1.5 134.5 2.36
8.0 83.2 1.54 3.0 102.4 1.74
12.5 73.8 1.39 4.7 89.4 1.53
18.5 66.8 1.28 7.0 79.8 1.38
27.0 62.3 1.23 10.2 73.6 1.32
38.3 58.4 1.19 14.5 68.2 1.25
54.3 55.2 1.15 20.6 63.7 1.21
77.1 52.3 1.12 29.0 59.7 1.17
109.2 49.8 1.09 41.1 57.1 1.14
146.0 48.2 1.08 55.2 55.1 1.12
187.0 46.8 1.07 70.7 54.0 1.11
239.0 45.6 1.06 90.3 53.3 1.10
305.0 44.5 1.05 115.3 53.1 1.09
390.0 43.5 1.04 147.4 52.8 1.09
498.0 42.6 1.04 188.2 52.6 1.08
635.0 41.8 1.03 240.0 52.3 1.07
Table 2: Buhlmann Z-Values.