A leak detection device for detecting leakage of a chamber includes a leak detection assembly, a first isolation valve, a suction pump and a second isolation valve. The leak detection assembly includes a gas sensor for detecting a first specified gas in the chamber. The first isolation valve is coupled between the chamber and the leak detection assembly to selectively permit and prevent fluid communication between the chamber and the leak detection assembly. The suction pump draws out air in the chamber to allow a pressure inside the chamber to be lower than a pressure outside the chamber. The second isolation valve is coupled between the chamber and the suction pump to selectively permit and prevent fluid communication between the chamber and the suction pump.

A tube infrastructure includes a first tube; a second tube that is coupled to the first tube; and a fluid tank that is disposed to surround a coupling region of the first tube and the second tube and is filled with a fluid to seal the coupling region, wherein the fluid tank allows negative pressure to be maintained inside the first tube and the second tube.

There is provided a fit testing method comprising: providing a respirator donned by a wearer; providing a sensor in electrical communication with a sensing element, where the sensor is configured to monitor a particulate concentration parameter of a gas space within the respirator, and a second particulate concentration parameter of a gas space outside the respirator, where the sensor is attached to the respirator such that the respirator such that the weight of the sensor is supported by the respirator; and providing a reader configured to communicate with the sensor, where the reader is configured to provide a respirator fit parameter based on a comparison of the particulate concentration within the respirator to the particulate concentration parameter outside the respirator.

A hydraulic cylinder unit (1) having a hydraulic cylinder (2), a piston (3) which can be moved in the hydraulic cylinder (2), and a servo valve (7). The piston (3) separates working volumes (5A, 5B) of the hydraulic cylinder unit (1) from one another. The servo valve (7) is connected to a hydraulic pump (8), a tank (9), and the working volumes (5A, 5B). The servo valve (7) is supplied with a pump pressure (pP) via the hydraulic pump (8). The tank (9) has a tank pressure (pT). The servo valve (7) is adjusted to a defined valve position (y). A piston position (z) of the piston (3) in the hydraulic cylinder (2) and working pressures (pA, pB) which are applied to the working volumes (5A, 5B) are detected. An analysis device (12) ascertains a leakage coefficient () of the hydraulic cylinder unit (1) using the piston position (z), the working pressures (pA,pB), the valve position (y), the pump pressure (pP), and a value which represents the tank pressure (pT) in connection with time-invariant parameters of the hydraulic cylinder unit (1).

Systems and methods of detecting leakage and other issues with electrical battery housings are provided. By using an air compressor to alter the air pressure within a battery housing, a processor may detect an abnormal rate of change in the air pressure within the battery housing as compared to a rate of change of an ideal battery housing.

A method and system of diagnosing the integrity of a sealed air tube of a pedestrian protection system of a vehicle is provided. The method provides the sealed air tube having a pressure sensor connected at each end of the air tube. The air tube is constructed and arranged to be located in front fascia of a vehicle. A processor circuit is electrically connected with the pressure sensors and the processor circuit has a Fast Fourier Transform element. Natural frequencies of a frequency spectrum of the air tube are obtained when no leak is known to be present in in the air tube. Signals from the pressure sensors are transformed into the frequency domain with the Fast Fourier Transform element. A leak is determined to be present in the air tube if frequencies other than the natural frequencies exist in the frequency spectrum of the air tube.

The respirator fit monitor described herein can be worn continuously by users so as to provide an indication as to how well their masks are fitting during use, thereby providing quantitative, wearable fit testers available for continuous use in real-life situations. The monitor includes a low-cost optical particle sensor assembly and controller unit for performing mask fit tests by comparing particle concentrations inside and outside of the mask. The fit test monitor is low cost and wearable, capable of dual sampling, capable of fit factor ratios well above 100, is battery powered and provides near real time measurements with a means for indicating the fit of the mask. The system includes wired or wireless communications for data logging, analysis and display capabilities.

A method of fit testing includes providing a respirator donned by a wearer, providing an aerosol generator with a known aerosol output parameter, providing an enclosure that is physically supported around the wearer's head, where the aerosol generator delivers aerosol with the known aerosol output parameter that is at least partially contained within the enclosure around wearer's head, providing a sensor in electrical communication with a sensing element, where the sensor is operably connected to the respirator, and where the sensor is configured to monitor a particulate concentration parameter within the respirator, and providing a reader configured to communicate with the sensor, where the reader is configured to provide a respirator fit parameter based on a comparison of the particulate concentration parameter to the known aerosol output parameter.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. The method includes opening a lid of a tank containing the flammable fluid. The method includes connecting a cable to a vehicle that includes a battery and a control unit. The method includes lowering, via the cable and through an opening of the tank, the vehicle through a vapor barrier within the tank and on top of the flammable fluid. The method includes disengaging the cable from the vehicle subsequent to the vehicle contacting a floor of the tank. The method includes removing the cable from the tank. The method includes performing, via the control unit of the vehicle, a tank inspection process under battery power, the tank inspection process comprising generating a map of the tank and determining a quality metric for a portion of the tank corresponding to a location on the generated map.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. The system includes a vehicle having a battery, a control unit, an inspection device having one or more conductors, and a ranging device. The inspection device receives, from the control unit, a command to initiate inspection at the first position on the map. The inspection device changes a magnetic field in the one or more conductors to induce loops of electric current that extend towards a portion of the tank corresponding to the first position on the map. The inspection device detects values corresponding to the induced loops of electric current at the portion of the tank corresponding to the first position on the map. The inspection device provides, to the control unit, the detected values to cause the control unit to determine a quality metric and store the quality metric.