Section 4 Refrigeration
Leak Detection
R-134a system leaks can be pinpointed by means of an
electronic leak detector or by bubble solution.
Electronic leak detectors for R-134a service are currently
available from several manufacturers. The least
expensive models are non-selective detectors that will
detect any type of emission or vapor present, regardless
of its chemical composition. Some non-selective
detectors designed for use with R-12 may have a much
lower sensitivity when used with R-134a. However, newly
designed detectors with good R-134a sensitivity are now
available. Be sure to consult with the manufacturer
before selecting or using a non-selective detector with
R-134a.
4-14
Halogen-specific detectors use a specialized sensor that
allows detection of compounds containing chlorine,
fluorine, bromine, and iodine without being activated
by other species. The major advantage of this type
of detector is a reduction in the number of "nuisance
alarms". Halogen-specific detectors are generally more
expensive than non-selective detectors but feature
higher sensitivity.
R-134a properties
The properties of R-134a are very similar to those of
R-12. The principal data for the two refrigerants are
shown in the chart below.