Practical Application; Leak Detection On The Air-Conditioning System; Measuring Range [Ppm]; Gas Diffusion At The Leak Spot - Herth+Buss ELPARTS 95980002 Notice D'emploi

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Practical application

The following example describes one possible application of the
gas detector.
8.1

Leak detection on the air-conditioning system

During leak detection on the air-conditioning system, the parts
provided (service coupling, hose, pressure reducer, gas cylinder)
are connected to the system.
Screw the pressure reducer by hand to the gas cylinder
<
insert the service coupling on the filling connector
<
open the gas cylinder valve slowly and fill the air-conditioning
<
system with forming gas 95/5. The filling pressure is about 5 bar
Briefly start the engine and start locating the leak using the gas
<
detector; After leak detection and elimination of the leak in the
system, we recommend evacuating the system again before filling
it with oil and refrigerant.
Always remember to heed the manufacturer's specifications when
refilling! The testing gas (forming gas 95/5) is completely harmless
for humans and the material. Caution: When handling the gas
cylinder, please observe the safety regulations - see label on the
gas cylinder.
8.2

Measuring range [ppm]

The high sensitivity of the gas detector enables detection of gas tra-
ces in the ppm range. 1 ppm, for example, is the quantity of 1 cm
gas in one m of air. With Herth+Buss Elparts gas detector, this di-
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mension is used for measurements up to 999 ppm. At the transition
to 1000 ppm, the display changes to Vol.% and switches to 0.1 Vol.%
(see the comparative values in the table below).
The dimension [ppm]: 1 ppm = 1 part per million
100% = 1.000.000 ppm
10% = 100.000 ppm
1% = 10.000 ppm
0,1% = 1.000 ppm
0,01% = 100 ppm
0,001% = 10 ppm
0,0001% = 1 ppm
8.3

Gas diffusion at the leak spot

At "Erdgas Südsachsen" in Chemnitz, interesting tests have been
carried out on the subject of gas diffusion in a room depending on
the escaping quantity. Since the tests were carried out in a room
without people moving about and with the windows and doors
closed, they have no formal value in practical situations. The slightest
air movement would have falsified the results.
The study intended to prove that, at a distance of only a few centime-
tres, – again depending on the amount of gas escaping – leak detec-
tion by proof of gas becomes impossible. The diffusion of the gas in
the air in the room quickly leads to "dilution" towards zero.
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