A method for testing a fuel cell stack includes providing a fluid, such as an ammonia-containing fluid, in a first reactant flow path in a first portion of the fuel cell stack, detecting the presence of the fluid using a detector, such as an ammonia detector, positioned within or adjacent to a second portion of the fuel cell stack that is separated from the first portion of the fuel cell stack and determining the presence of a defect in the stack based on detecting the presence of the fluid. Further embodiments relate to testing a fuel cell stack using a microphone that detects an audio signal indicative of a stack defect.

The invention relates to a method for detecting one or more leaks in a battery enclosure (101) of a battery (100), the battery (100) including at least one electrochemical cell (102) enclosed in the battery enclosure (101), or detecting one or more leaks in the at least one electrochemical cell (102) being in the battery enclosure (101) or separate from the battery enclosure (101). The method comprises the steps of obtaining gas, in particular air, from a surrounding of the battery (100) or from a surrounding of the at least one electrochemical cell (102) being in the battery enclosure (101) or separate from the battery enclosure (101), respectively, obtaining an analysis of the gas by analysing the gas with an analysis method and determining on the basis of the analysis whether the gas includes a signature of at least one constituent part of the at least one electrochemical cell (102), the signature indicating a presence of the at least one constituent part of the at least one electrochemical cell (102) in the gas. In case it is determined on the basis of the analysis that the gas includes the signature of the at least one constituent part of the at least one electrochemical cell (102), a leak in the battery enclosure (102) of the battery (100) or in the at least one electrochemical cell (102) being in the battery enclosure (101) or separate from the battery enclosure (101), respectively, is detected. In the analysis method, the gas is ionised by an ionisation source (31) with an ionisation method to ions and the ions are analysed in an analyser (32) by being separated according to one or more physical properties, wherein the ionisation source (31) is a chemical ionisation source and the ionisation method is a chemical ionisation method. The invention further relates to an apparatus (1) for detecting one or more leaks in a battery enclosure (101) of a battery (100) with the method according to the invention.

A universal leak detection method for detecting both small and large leaks. The method includes the steps of: injecting smoke and a detectable gas into a fluid system to pressurize the fluid system, the smoke and detectable gas both being capable of passing through a large leak in the fluid system, and the visual smoke particles being inhibited from passing through a small leak in the fluid system and the detectable gas being capable of passing through a small leak in the fluid system; and detecting a leak by detecting at least one of the smoke and the detectable gas, wherein detection of smoke is indicative of the fluid system having a large leak and detection of detectable gas without smoke.

Methods and systems are provided for reducing evaporative emissions from a vehicle by performing a fine leak test at a vehicle assembly plant. Fuel tank pressure generated after a green tank fueling event is monitored as the vehicle moves along an assembly line. A leak is determined based on a rate of pressure bleed-up over the duration, and accordingly the vehicle is directed to a repair station.

A seal testing system provides an indicator of the tightness of seals in packaging of the seal testing system includes at least partially light permeable thermoplastic film providing two flexible layers that are impermeable for liquid and that are circumferentially sealed to define chambers that store a seal testing fluid and that are interconnected via a narrowed intermediate passage. At least section of a seal between the film layers is weakened to allow release of the seal testing fluid when pressure is introduced in the chambers.

A method for detecting leaks within an underwater surface of a water filled swimming pool including the steps of: (1) providing a component defining a hollow interior, having an annular outer periphery and a central opening adapted to encircle the underwater surface and seal there against; (2) providing a fluid inlet leading into the interior of the component at an off-centered location on the component; (3) placing the annular outer periphery around the outer periphery of the underwater surface within the water filled swimming pool, sealing the component against the underwater surface; (4) maintaining the annular resilient member in a stationary position relative to the underwater surface; and (5) permitting depositing a dye solution into the water filled swimming pool proximate the fluid inlet.

A method for detecting damage to one or more components of a fluid-conducting device such as a pump assembly, valve or the like uses at least one odor sensor to detect an odor produced by one of the components and transmit an odor profile to an evaluation unit. The evaluation unit compares the odor profile with one or more characteristic odor profiles to determine whether an odor indicative of a degraded component is present. If the detected odor profile matches a characteristic odor profile match, an output signal is generated in an output unit.

A leakage sensitive arrangement to improve detection of a leakage of a substance includes an emission generating compound that is applicable on an outside of an enclosure encapsulating a substance from the surroundings. The applied emission generating compound is configured to be exposed to an activation energy resulting from leaking substance from the inside of the enclosure. The activation energy causes a chemical reaction of the emission generating compound. The chemical reaction actively produces an emission detectable by a detector.

In leak testing by an accumulation method, it is possible to reliably detect accumulated inspection gas, and the reliability of leak testing is enhanced by reduction in background or impurity gas. At least an openable/closeable part 29 of a capsule 20 is housed inside a chamber 10 of a leak testing apparatus 1. A test workpiece 9 is housed in the capsule 20. Gas inside the chamber 10 is evacuated by a vacuum pump 31. A detector 2 detects inspection gas contained in this gas. The capsule 20 is continuously sealed for an accumulation time Ta, the capsule 20 is thereafter opened, and a leak is evaluated on the basis of detection information after the opening by the detector 2.

In one aspect, systems for detecting a fuel leak are described herein. In some implementations, a system for detecting a fuel leak described herein comprises a fuel-containing vessel having an exterior surface and a carbon nanotube coating layer comprising photoluminescent carbon nanotubes disposed on at least a portion of the exterior surface of the fuel-containing vessel. The system further comprises a fuel-sensitive coating layer substantially covering the carbon nanotube coating layer. The fuel-sensitive coating layer is optically opaque or substantially opaque to wavelengths of light absorbed and/or emitted by the photoluminescent carbon nanotubes.