Which type of leak detector is NOT mentioned as a common method?

The correct answer identifies infrared leak detectors as a type of leak detection method that is not mentioned among the common methods typically used. Leak detection methods often include the use of electronic detectors, soap bubble techniques, and fluorescent methods, as these are well-established and widely used in various industries.

Electronic leak detectors are popular for their sensitivity and ability to detect small leaks. They work by sensing the presence of certain gases, making them effective for identifying leaks in systems handling refrigerants or gases. Soap bubble methods are also commonly used; they involve applying a soap solution to areas of potential leaks and observing for bubbles that indicate escaping gas or liquid. Fluorescent leak detection employs special dyes that fluoresce under UV light, easily highlighting leaks in systems.

Infrared leak detectors, while effective in some contexts, are less often mentioned as a standard method when compared to the others listed. Infrared technology is primarily used for detecting specific gases based on their absorption of infrared light, which may not be as widely recognized or communicated as the other three methods among industry professionals.