Both the pump and flame methods can give false results depending upon environmental contaminants near the test. Advancements in either technique constantly decrease the room for false positives.
Gases containing halogen, such as chlorofluorocarbon and hydrofluorocarbon, are common in industrial, automotive and commercial cooling systems. The majority of halogen leak detectors use an automatic pump to sample the air surrounding the equipment, as do many leak detectors, such as Freon leak detectors and vacuum leak detectors.
Some leak detector systems, like one that identifies helium leaks, can be automatic, semi-automatic or manual. No matter how the detector runs, the point remains that its purpose is to detect gases and identify the precise location of a leak. Once detected, the air is drawn through a metal or plastic tube and compared to preset samples.
These pumps are calibrated to different types of halogenated gases and can often be customized to fit the exact needs of a given appliance. One other testing variation involves a halide torch test. The flame, which is normally blue, changes to a greenish hue when the presence of a halogen is detected.
Refrigeration and cooling systems often contain hundreds of feet of tubing, particularly in industrial settings. Even in smaller systems the tubing that must be monitored for leaks is commonly in inaccessible sections of the equipment. The area where the tubing resides could also still be running while the tests are being conducted.
Nevertheless, identifying leaks is essential to these systems, since leaks can significantly decrease machine and system performance. If left unchecked, leaks can lead to appliance failure. For this reason many of the most popular halogen leak detectors are hand held and extremely portable. Hand held pump devices have two main parts, the body and the tubing. The tube is often made of bendable metal or plastic to fit into specific locations.
The body can be metal or plastic and houses the battery and testing components. Despite the benefits of portability, some large cooling and refrigeration systems may be continuously monitored with a fixed halogen leak detector. In some regions, constant monitoring is required as halogenated refrigerants increase ozone depletion. Although most halogenated refrigerants are not harmful to humans in small doses, large amounts can aggravate heart problems.