Panasonic PT-DZ12000U Operating Instructions Manual page 77

A comparison of signal levels for various counting gases
Counting Gas
Air
Ar
He
H
2
N
2
O
2
CH
4
Ne
Xe
Ne + 0.5 % Ar
Ar + 0.5 % C H
Ar + 0.8 % CH
Ar + 10 % CH (P-10)
Use this equation to calculate the current flow in amps for an
ion chamber.
1 mR/hr = 8.71E-16 x V x P x fill gas g / l
where; V is chamber volume in cc,
P is chamber pressure in mm Hg,
T is 273.15 + C,
fill gas density in grams per liter,
ù for fill gas
2 2
4
4
T x ù for fill gas
0
ù Factor
eV / ion pair
33.8
26.4
41.3
36.5
34.8
30.8
27.3
36.2
21.5
25.3
20.3
26.0
26.0
66
Gas Density
(g / L)
1.2928
1.8
0.183
0.09
1.25
1.43
0.717
0.9
5.9
0.909
1.75
1.78
1.616