Abstract: The invention relates to a leak indicator (1) comprising a housing (2) which houses components (3 to 6) of the indicator and a test leak (20), and to test leaks (20) that are suitable for integration into a leak indicator of the above-described kind.

Abstract: The invention relates to a method for detecting a test gas that may be present at a measuring location, using an infrared gas analyser (1) that comprises a cuvette (2), an infrared light source (3), an infrared detector (4), and two gas lines (15, 17). Said gas lines supply gases to the infrared gas analyser and one of said lines is adapted to take up a measuring gas at a measuring location that may contain a test gas. The second line (17) is adapted to take up gas from the surroundings of the measuring location (reference gas), which gas may contain a test gas background that is to be taken into consideration when detecting the test gas taken up at the measuring location. In order to improve the sensitivity of the analyser it comprises only one cuvette (2) and the measuring gas taken up at the measuring location and the reference gas are fed to the cuvette of the infrared gas analyser in such a manner that they are alternately present in the cuvette.