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Appendix
Appendix
Gas types
LEL values are specified in accordance with IEC 60079-20.
Methane CH
4
(100 % LEL = 4.40 % vol.)
Area of
application
Test gas
Tolerances / fresh
air zero point
Tolerances / test
gas indication
accuracy
ppm range
1.0 % vol. CH
4
in
synth. air
0 ppm
0.8 to 1.4 % vol.
% LEL range
2.2 % vol.
(50 % LEL) CH
4
in
synth. air
-0.15 to +0.15 % vol.
(-3 to +3 % LEL)
2.00 to 2.40 % vol.
(45 to 55 % LEL)
% vol. range 100 % vol. CH
4
-2 to +2 % vol.
98 to 102 % vol.
Propane C
3
H
8
(100 % LEL = 1.70 % vol.)
Area of
application
Test gas
Tolerances / fresh
air zero point
Tolerances / test
gas indication
accuracy
ppm range
1.0 % vol. C
3
H
8
in
synth. air
0 ppm
0.8 to 1.4 % vol.
% LEL range
1.0 % vol.
(59 % LEL) C
3
H
8
in
synth. air
-0.06 to +0.06 % vol.
(-3 to +3 % LEL)
0.90 to 1.10 % vol.
(53 to 65 % LEL)
% vol. range 99.5 % vol. C
3
H
8
-2 to +2 % vol.
98 to 102 % vol.
