SMC
sierra monitor corporation
Sentry Instruction Manual - Version 6
SERVICE
Page: 71
7.5.5 COMBUSTIBLE GAS SCALING FACTORS
For combustible gas monitoring, a calibration standard of Methane or Propane my be used in conjunction with scaling factors
to cause Sentry concentration display and alarm function in %LEL scale of another gas as follows:
GAS
METHANE
PROPANE
FACTOR
FACTOR
Acetaldehyde
60
109
Acetic Acid
54
98
Acetic Anhydride
46
83
Acetone
52
94
Acetylene
57
103
Alkyl Alcohol
51
92
Ammonia
126
229
n-Amyl Alcohol
33
59
Aniline
39
71
Benzene
41
74
Biphenyl
25
45
1,3-Butadiene
56
101
n-Butane
58
106
iso-Butane
52
94
Butene-1
45
82
cis-Butene-2
48
88
trans-Butene-2
51
92
n-Butyl Alcohol
34
62
iso-Butyl Alcohol
53
96
tert-Butyl-Alcohol
74
134
n-Butyl Benzene
31
57
iso-Butyl Benzene
32
58
n-Butyric Acid
38
69
Carbon Disulfide
18
32
Carbon Monoxide
75
137
Carbon Oxysulphide
93
169
Chlorobenzene
34
62
Cyanogen
89
162
Cyclohexane
41
74
Cyclopropane
62
113
n-Decane
33
59
Diethylamine
49
88
Dimethylamine
58
105
2,3-Dimethylpentane
40
72
2,3-Dimethylpropane
40
72
Dimethylsulphide
43
79
1,4-Dioxane
45
81
Epichlorohydrin
45
82
Ethane
68
123
Ethyl Acetate
51
93
Ethyl Alcohol
73
132
Ethylamine
53
95
Ethyl Benzene
36
65
Ethyl Bromide
91
165
Ethyl Chloride
57
103
Ethylcyclopentane
40
72
Ethylene
71
128
Ethylenedichloride
66
120
Ethyleneoxide
52
94
GAS
METHANE
PROPANE
FACTOR
FACTOR
Diethyl Ether
46
84
Dimethoxyethane
42
75
Dimethyl Ether
63
113
Dimethylformamide
46
83
Ethyl Formate
44
80
Ethylmercaptan
56
102
n-Heptane
39
70
n-Hexane
37
67
Hydrazine
45
82
Hydrogencyanide
48
86
Hydrogen
77
139
Hydrogen Sulfide
41
74
Methane
100
181
Methyl Actetate
50
90
Methyl Alcohol
86
156
Methylamine
77
140
Methyl Bromide
90
162
Methyl Chloride
102
186
Methylcyclohexane
44
80
Methylenedichloride
93
168
Methylethylether
44
80
Methylethylketone
41
75
Methyl Formate
67
121
Methylmercaptan
61
110
Methylpropionate
51
93
Methyl n-propylketone
40
73
Napthalene
34
62
Nitromethane
34
62
n-Nonane
31
57
n-Octane
37
68
n-Pentane
46
83
i-Pentane
46
84
Propane
55
100
n-Propyl Alcohol
47
85
n-Propylamine
48
88
n-Propylchloride
50
90
Propylene
52
93
Propyleneoxide
46
83
iso-Propylether
44
79
Propyne
42
75
Toluene
40
73
Triethylamine
40
72
Trimethylamine
48
88
Vinylethylether
42
76
o-Xylene
36
65
m-Xylene
39
71
p-Xylene
39
71
JP-4 (Jet Fuel)
41
73
NOTES:
1. Scaling factors are not FMRC approved.
2. Base data source: EEV sensor specification catalog. (EEV claims some data is the result of specific tests, other
data is empirically derived.)