Relative humidity (%)

σDC

εs − ε

τ

β

100

4.0 × 10−3

2.0 × 103

1.0 × 10−6

0.40

81

5.0 × 10−5

9.1 × 102

1.9 × 10−5

0.60

53

1.0 × 10−5

8.7 × 102

8.1 × 10−5

0.63