INFICON Extrima Ex-certified Hydrogen Leak Detector - Manual (Page 9)

9
EN
INFICON - Operating Instructions EXTRIMA
When a mixture of less than 5.5% hydro-
gen in nitrogen mixes with air there is
not sufficient energy to support a flame,
irrespective of the ratio of air-to-gas.
When a mixture of more than 5.5%
hydrogen in nitrogen is released into air
there is a region of ratios of air-to-gas
where the mixture is flammable. When,
for example, a mixture of 10% hydrogen
in nitrogen mixes with air there is still
very little energy available.
Only in exceptional circumstances can
a flame be self-supporting, even for a
10% hydrogen mixture. However, such
mixtures cannot detonate.
NOTE: Whenever the word Hydro-
gen tracer gas is used throughout
this manual it implies that the
hydrogen gas is safely mixed with
Nitrogen in the proportions 5%
H
2
- 95% N
2
.
Hydrogen/nitrogen mixtures containing
more than approximately 15% hydrogen
con detonate when mixed in certain pro-
portions with air.
WARNING!
Never use a gas mixture con-
taining more than 5% hydro-
gen.
Never make your own gas
mixtures. Only use ready-made
mixtures, or use a certified hy-
drogen/nitrogen mixer installed
by your gas supplier.
Hydrogen Tracer Gas for leak detection