6
1 General
1.6
Tracer gas method
A
NOTICE!
This section provides only a brief overview of the tracer gas
method. Using the tracer gas method correctly requires
extensive specialist knowledge.
The tracer gas method can be used for leak detection and for
leakage tests.
The method uses a nitrogen/hydrogen gas mixture (tracer gas)
consisting typically of 5% hydrogen and 95% nitrogen. Gas mix-
tures containing 10% hydrogen and 90% nitrogen can also be
used, however.
Owing to its physical properties, hydrogen has the ability to pen-
etrate other materials (e.g. screed, concrete). This penetrating
power is used to locate gas leaks in closed systems with a gas
measuring device such as the
VARIOTEC 460 Tracergas
.
Such closed systems may either already exist (e.g. filling stations)
or may have to be created. In the latter case the pipe sections
to be inspected are closed off with blind flanges, for example.
Although pure hydrogen is extremely flammable, tracer gas is
non-combustible, non-corrosive and non-toxic. Hydrogen is ap-
proved as a food additive (E949), making the tracer gas method
suitable for inspecting water pipes.
