Cyclic perfluorocarbons, such as perfluoromethylhexane and perfluoro-1,3-dimethylcyclohexane, are generally believed to be better than acyclic ones as they can be detected at lower levels.
There are two ways in which the PFTs are then detected; using an electron capture detector or negative ion mass spectrometry.
Traditional underground high-tension cables are constructed either with internal oil ducts or channels or by the use of a pipe through which the insulated conductor is installed.
The leak is initially identified by the loss of liquid from the system, and its location involves engineers digging up the road, freezing a section of the cable and seeing if the level is still going down, then choosing a new point to dig and re-freeze, which could take several holes to isolate the leak.
[3] PFTs have been used to follow air movement, for tracing the flow of pollutants, for example, the Big Bend Regional Aerosol and Visibility Observational study,[4] measuring the effectiveness of ventilation and studying the possible effects of terrorist attacks (for example in New York ).