A leak detector employing an ion-conducting membrane is disclosed. A labelled-gas ion conducting membrane which employs a high vacuum on one side is used to detect very small quantities of said labelled-gas flowing through a minute fissure in a part or device to be tested for leaks. The labelled-gas ion conducting membrane is biased with direct current voltage to drive the labelled-gas ions through the membrane away from the high vacuum side.

This invention relates to a method and an apparatus for sealing a port of a vessel, which apparatus comprises: (a) a seal for forming a gas-tight seal with the port to close off the port, (b) a chamber; and (c) a chamber sweeping gas for sweeping the chamber.

This invention relates to a process and apparatus for repairing a port of a vessel, the port having an inside surface which is damaged. The method and apparatus utilize a liner means for lining the inner surface of the port, a sealed chamber between the lining means and the inner surface of the vessel port, a means of using a gas, preferably an inert gas, to purge the sealed chamber, and a means of monitoring the gas which is purged from the chamber.

A method and apparatus detects and locates perforations in membranes used in electrochemical cells. The membrane has first and second oppositely facing major planar surfaces. The first surface is exposed to a first reactant fluid, preferably a gaseous mixture comprising hydrogen, while the second surface is exposed to a second reactant fluid, preferably ambient air comprising oxygen. The first and second reactant fluids are substantially fluidly isolated from each other by the membrane when no perforations are present in the membrane. The first reactant fluid contacts the second reactant fluid when at least one perforation is present in the membrane. The first and second reactant fluids exothermically react upon contact, preferably in the presence of a catalyst, to generate heat, which is then detected using an infrared thermal detector or thermal imaging device or a layer of thermally sensitive film positioned in proximity with the membrane.

A method and system for detecting imperfections in a membrane electrode assembly of an electrochemical fuel cell, and more particularly for detecting defects within a proton exchange membrane in a membrane electrode assembly which is optionally sandwiched between conductive diffusion media layers or between conductive diffusion layers with at least one rigid solid that is transparent to infrared radiation. A potential voltage is applied across the membrane and the presence of a defect and preferably the location of a defect is determined by monitoring variations in intensity level of infrared radiation emitted from a surface of the membrane electrode assembly.