Inficon CU1000

INFICON Operation CU1000 | 6
CU1000-Operating-Instructions-jina54en1-09-(2404) 29 / 46
ð This is the gas proportion of the tracer gas in percent, e.g. for forming gas
(95/5) it would be 5%.
7 Window "Absolute pressure measuring gas".
ð Corresponds to the absolute pressure of the tracer gas in the test object in
bar.
Example
An air conditioning system is to be checked for leaks. The system is first filled with 2
bar (absolute) pure helium and checked for leaks. Later the plant will be filled with
R134a. The operating pressure is 15 bar (absolute).
This results in the following values for the above-specified parameters:
Absolute pressure equivalence gas = 15.0
Measuring mass = 4
Percentage of measuring gas = 100.0
Absolute pressure measuring gas = 2.0
6.3.6.3 Calculate equivalence factor
The equivalence factor is not calculated by the software of the device. Calculate the
equivalence factor using the following formula:
Dynamic viscosity of test gas (helium or H
2
)
Dynamic viscosity of the equivalent gas
Absolute pressure of the test gas in the test object in bar
Absolute pressure of the equivalent gas in the test object in bar
Example An air conditioning system is to be checked for leaks.
The system is first filled with 2 bar (absolute) helium and checked for leaks. Later the
plant will be filled with R134a. The operating pressure is 15 bar (absolute).
The dynamic viscosity of helium is 19.62 µPa*s.
The dynamic viscosity of R134a is 11.49 µPa*s.
In order to obtain an R134a equivalent leak rate display during the helium leak
detection, the following equivalence factor must be entered: