Leak detection device

A leak detection method for detecting a leak in a test zone of a sealing membrane of a tank with the aid of a leak detection dome,

• the leak detection dome including a main body and a seal connected to the main body and configured to define a detection chamber between the main body and the sealing membrane, the seal including a peripheral sealing lip configured to come into contact with the sealing membrane and having a closed contour encircling the detection chamber, the leak detection dome further including a mechanical pressure means carried by the main body and including at least one pressure element configured to exert on a portion of the sealing lip a pressure directed toward the membrane when the main body is disposed in the test zone,
• the detection dome comprising a support element (73) fixed to the main body (100), the pressure element comprising a body (89) fixed to the support element (73), a rod (90) mounted to be mobile in translation relative to the body (89), a spring (86) urging the rod (90) towards the sealing lip (64) and a bearing element (91) fixed to one end of the rod (90) and coming to bear against the sealing lip (64) under the effect of the spring (86),
• said sealing membrane including a plurality of corrugated or plane metal plates that are welded to one another,
• the leak detection method including the following steps:
• disposing the detection dome against the sealing membrane so as to position the detection chamber in line with at least one weld bead between a first metal plate and a second metal plate and positioning the pressure element to exert the pressure on a portion of the sealing lip that crosses said weld bead,
• reducing the pressure in the detection chamber by means of a vacuum pump,
• conveying the gas phase contained in the detection chamber to an analysis tool to detect a gas present in the detection chamber.