Abstract: There is provided a method of channel leakage detection in a medical device having one or more channels and a housing having an internal volume surrounding at least a portion of the one or more channels, comprising the steps of (a) pressurizing one or more of the channels by introducing air or gas into the channel; and (b) detecting leakage by monitoring pressure increase in the internal volume of the housing.

Abstract: A leakage diagnosis apparatus is applied to an evaporated-gas purge system including a negative-pressure sensor and a pressure detecting portion. The negative-pressure sensor introduces a negative pressure into an evaporation system. The pressure detecting portion detects the pressure in the evaporation system. The leakage diagnosis apparatus includes a leakage-diagnosis portion and a determining portion. The leakage-diagnosis portion executes a leakage diagnosis to determine whether a leakage of the evaporation system is generated. The determining portion determines whether an evaporated-gas amount in the evaporation system is in an excessive state while the internal combustion engine is stopped. The leakage-diagnosis portion prohibits or terminates the leakage diagnosis, when the determining portion determines that the evaporated-gas amount is in the excessive state.

Abstract: An ECU determines whether condensed water is present at a rotor and vanes based on an electric current, which flows in an electric motor that drives the rotor. When the condensed water is determined to be present, the ECU drives the motor for a predetermined time period. When the condensed water is determined to be absent, the ECU stores a pressure, which is sensed through a pressure sensor, as a first pressure. The ECU is adapted to sense an abnormality in a pump characteristic based on a value of the first pressure.

Abstract: An apparatus for treating a medical liquid includes a treatment machine having a coupling surface and a flexible mat arranged on the coupling surface, with a cassette made of a hard part having liquid-conducting passages therein which are covered by a flexible film that is couplable to the coupling surface of the treatment machine via the flexible mat. The apparatus includes an element for monitoring a fault-free coupling to the cassette at the coupling surface by determining a difference of the pressure between the cassette and the flexible mat and the pressure between the flexible mat and the coupling surface. A method for checking the leak tightness of the fault-free coupling employs the apparatus.

Abstract: A leak detection system having power and communication lines includes a leak sensing cable having sensor lines for sensing a leak, detection controllers connected to the sensor lines to detect a leak position signal, and a master controller receiving the detected leak position signal from the detection controllers, wherein the leak sensing cable includes power and communication lines that are wired to supply power to the detection controllers via the master controller and to transmit the leak position signal to the master controller from the detection controllers. According to this invention, the leak detection system has power and communication lines that are able to transmit the leak position signal between the detection controllers and the master controller while supplying power to the detection controllers and the master controller.

Abstract: A battery pack with a drain plug and a circuit to detect when a liquid coolant has entered the battery pack. The drain plug includes a carrier defining a cavity internal to the carrier, an inlet disposed on a first surface of the carrier and an outlet disposed on a second surface of the carrier where the first surface and the second surface fluidly displaced from one another and coupled to the cavity. A soluble plug may be disposed within the cavity of the carrier; the soluble plug is configured to at least partially dissolve when fluidly coupled with a coolant allowing a portion of the coolant to flow between the inlet and the outlet and out of the battery pack. A strain gauge cooperative with the carrier such that a measured resistance change in the strain gauge corresponds to the soluble plug in contact with the liquid coolant. An associated circuit with the drain plug provides notification of the activation of the drain plug to the on-board computer systems.

Abstract: A fuel leakage detection system comprises: a communication part for acquiring data relating to fuel filling of an onboard fuel tank from the vehicle side when a fuel supply part is connected to a filler port; a fuel flow rate measurement part, provided on the upstream of the fuel supply part 18, for measuring the flow rate of fuel flowing to the fuel supply part; a fuel flow-out permission part for permitting/stopping the outflow of fuel to the fuel supply part; and a control unit for controlling the fuel flow-out permission part. The control unit further comprises a fuel leakage detection part for detecting fuel leakage when filling fuel to a vehicle based on the fuel flow rate acquired by the fuel flow rate measurement part and on data relating to fuel filling acquired from the vehicle side via the communication part, and the fuel flow out permission part stops outflow of fuel to the fuel supply part when occurrence of fuel leakage is detected by the fuel detection part.

Abstract: A tube weld seam test method and device for testing a tube weld seam (32) of a flexible tube (18) for leaks having: a first pinching device (10) and a second pinching device (12) for pinching closed the flexible tube (18) at a first position (A) and at a second position (B), the weld seam to be tested being arranged between the first and second positions (A; B); a compressing mechanism arranged for partly compressing a tube section enclosed between the first and second pinching devices (10; 12); and a pressure test device (14) arranged for testing an internal pressure of said tube section in order to test the tube weld seam for leaks.

Abstract: A leak detector comprises a cell provided with a tracer gas inlet preferably permeable to a tracer gas. In the cell, the tracer gas is caused to assume an energetically higher metastable state. By means of laser spectroscopy the absorption spectrum of the metastable tracer gas is sampled in an optical measuring section, whereby the presence of tracer gas is detected.

Abstract: An emissions control system is provided that comprises a fuel tank, a hydrocarbon filter element, and a three-way valve coupled between the hydrocarbon filter element and the atmosphere. The three-way valve is comprised of three ports, a purge port, a reference port, and a sealed port, and enables identification of degradation of the emissions control system. The arrangement of the ports on the valve enables a simplified testing method that reduces background errors caused by transitioning between various operating positions.

Abstract: A sniffing leak detector which comprises a first suction line in a sniffing probe, the line leading to a main device, is provided with a larger second suction line through which gas is sucked in from the sniffing tip by a gas delivery pump. By connecting the second suction line, the distance sensitivity is increased. By disconnecting the second suction line, on the other hand, the sensitivity is increased. Thus, it is possible to first search for leaks by use of a high gas throughput and subsequently exactly determine the leaks under the quantitative aspect by use of a reduced flow.

Abstract: A test pressurization device (100) for hose (1) includes a first pair of press/driving rolls (10, 12) between which the hose can be inserted, and a second pair of press/driving rolls (20, 22) between which the hose can be inserted. The first pair of press/driving rolls (10, 12) is arranged on a distance from the second pair of press/driving rolls (20, 22). Further each pair of press/driving rolls is arranged for pressing the hose together between the rolls in conjunction with pressurization with a medium such as water so that a limited part of the hose, which is located between the first and the second pair of press/driving rolls, can be held pressurized and control of the hoses or its couplings tightness is admitted. Furthermore, while sections of the hose are held pressurized between the pairs of press/driving rolls, the same pairs of press/driving rolls are feeding the hose forward, thus checking the hoses tightness in a continuously moving section approach.

Abstract: A seal monitoring and control system for a gas lubricated non-contacting seal includes various sensors providing signals to a programmable logic control system. The control system is disposed to determine a presence of an anomalous operating condition of the seal, for example, based on phase, relative position of rotor to stator or other signals in combination provided by the various sensors to provide an output signal, which in one embodiment performs at least one mitigating process to correct the anomalous operating condition by adjusting at least one operating parameter of the seal.

Abstract: A method and apparatus for detecting leakage of flowing liquids from pipes includes an upstream flow-rate sensor positioned between a source of a flowing liquid which is conducted from a source to a destination terminal such as a VAV heat exchanger, and a downstream flow-rate sensor positioned between an outlet port of the destination terminal and a return line for the flowing liquid. The apparatus includes electronic control circuitry which is responsive to a differential flow-rate between upstream and downstream measured flow rates which exceeds a predetermined limit value in removing a valve-opening signal to the upstream shut-off valve, thus closing the valve to interrupt flow of liquid through the valve if the differential flow-rate signifies a leak. Optionally, the apparatus also includes a downstream shut-off valve positioned between the destination terminal and a return line, which is also closed in response to a differential flow-rate exceeding the limit value.

Abstract: A method is provided to diagnose a fault in a fuel injection system of an internal combustion engine. The method includes, but is not limited to commanding an injection pulse for injecting a test quantity of fuel into an engine cylinder, determining the torque released to an engine crankshaft due to the injection pulse, calculating the difference between this released torque and an expected value for the torque, and of detecting a fault in the fuel injection system if the difference exceeds a threshold.

Abstract: A fluid transfer device and methods and apparatuses for making same is provided. The fluid transfer device comprises a conduit configured to transfer a fluid. The fluid transfer device further comprises a sheath surrounding the perimeter of the conduit and extending along at least part of the length of the conduit. In some embodiments, the interior of the sheath may be grooved to facilitate movement of the fluid from the location or locations of a leak or leaks along the length of the fluid transfer device. The sheath comprises one or more leak detection portions configured to provide an indication of fluid leaking from the conduit.

Abstract: A gas tightness testing member disposed in an electronic device includes a first end, a second end, and a fluid channel penetrating from the first end to the second end. The second end of the gas tightness testing member is combined with the electronic device, and the first end is connected to a gas tightness testing device for performing a gas tightness test.

Abstract: A method of measuring a flow rate of a first fluid through a rotary seal of a gas turbine engine comprising controlling a probe flow of a second fluid at an intra-seal cavity and measuring a pressure change in the first fluid caused by the probe flow.

Abstract: A reconfigurable leak testing system includes a leak testing station, an off-shuttle disposed adjacent to the leak testing station, and a fixture cartridge that is translatable between the off-shuttle and the leak testing station. The fixture cartridge is configured to selectively couple with the leak testing station and includes an upper fixture, a lower fixture, and a plurality of actuatable testing features. The fixture cartridge is configured to receive a part between the upper fixture and lower fixture, and the plurality of actuatable testing features are configured to contact the received part to create a closed volume adjacent the part, wherein the closed volume may be pressurized via a pressurized fluid, and examined for leaks.

Abstract: A leak detection device has a test chamber which, for evacuation, is connected to an evacuation pump device. Moreover, the test chamber is connected by a test gas line to a test gas pump device. The test gas pump device is connected, at its main inlet, to a test gas detector, such that a detection of test gas can take place using the counter-current principle. A valve device is arranged in the test gas line. This valve device has a test gas chamber for temporary storage of test gas removed from the test chamber.

Abstract: A method for detecting leak from a fuel vapor treating apparatus defining a first area including a fuel tank and a second area including an adsorbent canister has hermetically closing the first area, measuring internal pressure of the first area, comparing an absolute value of differential pressure between the internal pressure of the first area and the atmospheric pressure with a predetermined value, measuring the internal pressure of the first area in a case that the absolute value is equal to or higher than the predetermined value in order to check for leaks from the first area based on changes in the internal pressure of the first area, fluidly communicating the first area with the second area in order to equilibrate internal pressures of the first area and the second area, hermetically closing the second area, and measuring the internal pressure of the second area in order to check for leaks from the second area based on changes in the internal pressure of the second area.

Abstract: A zone-control unit for use in a heating, ventilation, and air conditioning (HVAC) system, the zone-control unit includes a heat exchanger, an inlet piping assembly coupled with the heat exchanger for supplying fluid to the heat exchanger, an outlet piping assembly coupled with the heat exchanger for receiving fluid from the heat exchanger, a bracket that maintains the inlet piping assembly and the outlet piping assembly in positional relationship, and an ancillary component coupled with the heat exchanger.

Abstract: A head form for testing a variety of respirators. The head form can prevent false leak failures by having a mask registration member upon which the mask under test is mounted, the mask registration member being self lubricating. In one embodiment, the registration member is an inflatable bladder. The bladder can be configured to limit lift away of the inflatable bladder from the recess, thereby mitigating leaks in the head form assembly. The bladder may be configured to limit roll away of portions of the bladder that register against the head form, thereby reducing or eliminating leaks between the inflatable bladder and the mask under test.

Abstract: A method for producing a composite structure comprising fiber reinforced material by means of vacuum assisted resin transfer molding is described. The fiber material is impregnated with liquid resin, and the method comprising the steps of: a) providing a forming structure comprising a rigid mold part and a second mold part, b) placing the fiber material in the rigid mold part, c) sealing the second mold part against the rigid mold part to form a mold cavity, d) connecting a source of uncured fluid resin to at least one resin inlet communicating with the mold cavity, e) connecting at least one vacuum outlet communicating with the mold cavity, f) evacuating the interior of the forming structure through the at least one vacuum outlet, g) supplying uncured resin from the source of uncured resin to the mold cavity through the at least one resin inlet so as to fill the mold cavity with resin, and h) curing the resin in order to form the composite structure.

Abstract: A method for determining the flow of an anode gas out of an anode sub-system. The method includes providing pressure measurements at predetermined sample times over a predetermined sample period and using the pressure measurements to calculate a slope of a line defining a change of the pressure from the beginning of the time period to the end of the time period. The slope of the pressure line is then used in a flow equation to determine the amount of gas that flows out of the anode sub-system, which can be through a valve or by system leaks.

Abstract: Closed containers which are filled with a consumer product are tested on leakiness by means of mass spectrometry (10) in that an impact (AN(P)) by the consumer product (P) upon the surrounding atmosphere (A(P)) of the container to be leak tested is monitored by the mass spectrometry (10).

Abstract: A pressure-based tester for testing an integrity of a printhead integrated circuit (IC) carrier includes a housing assembly; a cradle assembly coupled to the housing assembly and adapted to receive the printhead IC carrier, the cradle assembly further defining spouts adapted to engage with the printhead IC carrier; a regulated gas supply arranged in the housing assembly; a first gas supply line in fluid communication with the regulated gas supply; a pneumatic retaining mechanism in fluid communication with the gas supply via the first gas supply line, the pneumatic retaining mechanism for retaining the carrier in fluid communication with the spouts during testing of the platform assembly; a second gas supply line in fluid communication with the regulated gas supply, the second gas supply line being separated from the first gas supply line by a pressure regulator, the second gas supply line for supplying gas to the spouts; a pressure sensor for measuring a gas pressure at each spout and generating a signal ind

Abstract: A waterproof testing system and a method thereof are provided. The method includes a master device controls a gas tester to adjust gas pressure for a sample; when the master device determines an effect pressure value is equal to a goal pressure value, the master device controls the gas tester to adjust gas pressure for the sample to the goal pressure value continuing in a first length of time; the master device determines whether the effect pressure value still maintains within a first pressure range; if yes, the master device controls the gas tester to stop adjusting the gas pressure for the sample; the master device determines whether the effect pressure value maintains within a second pressure range; if yes, the master device determines a time the effect pressure value maintains within the second pressure range exceeded a second length of time; and if yes, the waterproof test is successful.

Abstract: A leak detection system is provided for detecting a leak in a fuel line. A controller determines the presence of a leak in the fuel line based on an analysis of data obtained from individual leak tests performed on the fuel line, the individual leak tests may span one or more fuel delivery events.

Abstract: A self contained unit and system for determining whether medical equipment or devices such as endoscopes, minimally invasive surgical instruments (MIS), etc., are blocked, or substantially free flowing, or are disconnected or leaking before they are subjected to cleaning and/or a disinfecting process that is either sequential or simultaneous. The apparatus has a manifold that generally receives predetermined amounts of a gas and/or liquid for dispensing to one and preferably a plurality of channels. Advantageously, the test apparatus of the present invention can be utilized as a stand-alone unit that is able to monitor the noted medical equipment or devices with regard to the flow of a gas and/or liquid therethrough such as large or small lumens and such flow can also be automatically verified by a system independent of human intervention. Alternatively, the test apparatus can be utilized as part of a comprehensive system in conjunction with other devices for testing, cleaning, and/or disinfecting.

Abstract: Methods and systems are provided for detecting a fuel system leak. While a system vacuum pump is operated to supply vacuum to a vacuum consumption device, air exhausted from the vacuum pump is routed to a fuel system to apply positive pressure thereon. A fuel system leak is identified based on a rate of decay of the pressure applied from the vacuum pump.

Abstract: Methods and apparatus for detecting a leak in a gas precharged hydraulic accumulator having an initial gas charge entail activating a hydraulic pump to charge the gas precharged hydraulic accumulator and the hydraulic circuit associated with the gas precharged hydraulic accumulator when the hydraulic circuit and the hydraulic accumulator have a temperature that is substantially equivalent to an ambient temperature, e.g., on a cold start. The hydraulic pressure in the hydraulic circuit is monitored, and when a step in the hydraulic pressure is detected, various quantities are measured and used to determine a volumetric efficiency of the pump for use in later calculations of remaining gas amount.

Abstract: The invention provides a system for leak detection of a fluid in a pipe network. The system includes flow meters, and vibration detectors adapted to be attached to a pipe at a location in the pipe network. A processor analyzes signals generated by the flow meters and vibration detectors to identify the presence of one or more leaks in the pipe network. The invention also provides a method for detecting and localizing leaks in a pipeline network, and a device comprising a flow meter integral with a vibration detector for use in the system of the invention.

Abstract: A device for testing pneumatic circuits and for measuring the leakage rate from reference pressure lines onboard an aircraft, connected to a plenum chamber. The device includes a multi-pressure system, comprising several sensors each connected to a reference pressure line, first solenoid valves arranged on the input channels to this multi-pressure system, and connected to the reference pressure lines through first connectors, second solenoid valves arranged on the reference pressure lines, a pressure controller module that is connected to all the first solenoid valves through a second connector, an electronic board that controls the solenoid valves and calibration of the multi-pressure system, a control device. The invention also relates to a method making use of this device.

Abstract: A system and method for determining whether an anode injector that injects hydrogen gas into an anode side of a fuel cell stack has failed. The method includes monitoring a voltage of the fuel cell stack and performing spectral analysis of the stack voltage to identify amplitude peaks in the stack voltage. The method further includes determining whether the spectral analysis of the stack voltage has identified an amplitude peak at a location where an amplitude peak should occur if the injector is operating properly. If no amplitude peak is identified at that location, then the method determines that the injector is not operating properly. If an amplitude peak is identified at that location, then the method compares the amplitude peak to the desired amplitude peak to identify if it is within a threshold to determine if the injector is operating properly.

Abstract: By monitoring pressure transients in a liquid within a liquid distribution system using only a single sensor, events such as the opening and closing of valves at specific fixtures are readily detected. The sensor, which can readily be coupled to a faucet bib, transmits an output signal to a computing device. Each such event can be identified by the device based by comparing characteristic features of the pressure transient waveform with previously observed characteristic features for events in the system. These characteristic features, which can include the varying pressure, derivative, and real Cepstrum of the pressure transient waveform, can be used to select a specific fixture where a valve open or close event has occurred. Flow to each fixture and leaks in the system can also be determined from the pressure transient signal. A second sensor disposed at a point disparate from the first sensor provides further event information.

Abstract: A pressure and prevacuum testing system for an AC system in a vehicle includes an air pressure source for pressurizing a cooling circuit of the AC system to a predetermined high pressure threshold and a vacuum source for prevacuuming the cooling circuit either to a predetermined prevacuum low pressure level or for a predetermined time period. The system also includes a pressure gauge for operatively measuring a pressure level in the cooling circuit. A controller is operatively connected to the air pressure source, the vacuum source and the pressure gauge. The controller compares the pressure level as measured by the pressure gauge to the predetermined high pressure threshold during a pressurized test of the cooling circuit and to the predetermined prevacuum low pressure level during a prevacuum test of the cooling circuit to determine if leaks are present in the cooling circuit.

Abstract: A test accessory for testing a variety respirators. The accessory is designed to compliment existing equipment to provide a robust assessment of respirator performance. The accessory may include a head form having an inflatable bladder capable of fitting a variety of sizes of respirator masks. In some embodiments, the inflatable bladder does not rely on adhesives to effect a seal, thereby eliminating manufacturing and quality assurance steps. The test accessory may also include a detachable instrumentation module that may be removed from the accessory, enabling calibration and maintenance at a remote facility without need for transporting the entire unit. The module may also house a memory device that may be upgraded with calibration data and firmware during the calibration process.

Abstract: A method and system for using an existing open-environment hydrogen sensor for detecting hydrogen leaking from an atmospheric reference port of a pressure regulator. The atmospheric reference port extension tube of one or more pressure regulators in a hydrogen storage system is routed past a hydrogen sensor which is already used to monitor air around the hydrogen storage system for the presence of hydrogen. In this configuration, the open-environment hydrogen sensor can quickly and reliably detect hydrogen gas flowing from the atmospheric reference port of one of the pressure regulators in the event a pressure regulator develops an internal leak.

Abstract: A device comprising a pressure monitor and a control means that receives a signal representing measured pressure at the pressure monitor and controls the controllable elements of a fluid system is utilized to monitor a fluid system for error conditions, to optimize operations and to diagnose the fluid system. By following a testing protocol that selectively enables parts of the system, the control means narrows the list of possible failing components. Comparing the measured pressure against normal pressures allows the device to identify error conditions. Determining the volume of fluid being transported and controlling the duration of the flow optimizes operation of the fluid system.

Abstract: Presently disclosed are methods and systems for detecting and diagnosing a coolant leak of an engine. A method may include diagnosing a coolant leak of the engine based on a low frequency pressure response of a measured engine coolant pressure. A vehicle system is also disclosed, including an engine, a coolant system operatively connected to the engine. The coolant system includes a coolant reserve and a coolant pump between the engine and the coolant reserve. The vehicle also includes a coolant pressure sensor to measure coolant pressure, and a controller configured to measure an engine coolant pressure and diagnose a coolant leak of the coolant system based on a low frequency pressure response of the measured engine coolant pressure.

Abstract: A leakage detection device comprises a cuff of an elastic material for being circumferentially wrapped around a region of a fluid-carrying conduit, wherein the cuff has an inner surface and an outer surface, through which at least one opening extends. At least one holder that comprises at least one guide element for guiding a measuring element over the opening is arranged at the edge of the opening. In this way, the measuring element can be positioned at a predetermined radial distance from the opening.

Abstract: A system comprising an engine including a chamber; an air intake coupled to the engine; a pressure sensor disposed in fluid communication with the air intake and disposed between the air intake and the chamber; and a processor configured to determine a breach in a ventilation system of the chamber in response to the pressure sensor.

Abstract: The present invention relates to an oil leak detection device. In an aspect, the oil leak detection device includes a base film layer 200 configured in a tape form, a pair of polymer lines 220, 230 formed on a top surface of the base film layer in parallel in a length direction, a pair of conductive lines 210, 240 formed on the top surface of the base film layer in parallel to the pair of polymer lines in the length direction, and an upper protection film layer 300 attached to the top surface of the base film layer and configured to have a plurality of sensing holes 310 formed at specific intervals in the length direction at locations through which only one of the pair of polymer lines is exposed.

Abstract: Hydrostatic testing tool and methods for testing a test article, such as a hose or container having an external threaded aperture. The preferred testing tool includes a housing, a piston and a collet body having a plurality of collet segments collectively forming a cylindrical inner perimeter having a variable diameter, each collet segment having a threaded surface on the inner perimeter such that the piston can selectively actuate the collet body to vary the diameter of the inner perimeter. In preferred embodiments, the hydrostatic testing tool utilizes a handle assembly that is arranged and configured such that only one hand is needed to operate the hydrostatic testing tool.

Abstract: A speaker leak test system which quickly tests if a speaker enclosure is sealed properly. The speaker leak test system tests for air leaks in the speaker enclosure, which air leaks degrade the acoustic performance of the speaker. A vacuum (or pressure) source is connected through a vacuum hose to the speaker enclosure and vacuum is drawn. After a test vacuum level is reached, the mass air flow through the vacuum hose is measured. If the mass air flow does not exceed a pre-determined speaker dependent threshold for the speaker under test, the speaker is declared to be leak free. A bypass solenoid may reside in parallel with a mass air flow sensor to reach test vacuum quickly. This speaker leak test system is intended to be used in a prototyping and production environment and tests the speaker enclosure for leaks both quickly (e.g., less than five seconds) and accurately.

Abstract: A leak detecting apparatus for detecting flaws in a surface submerged in liquid is provided that includes a vacuum head for contacting the surface and forming a vacuum chamber filled with liquid between the surface and the vacuum head, the vacuum head including a multi-surface elastomer seal for contacting the surface; and a vacuum generator for pulling gas through a flaw in the surface into the vacuum head and to the gas separation chamber so as to displace the liquid from the gas separation chamber. A method for detecting flaws in a surface submerged in liquid is also provided.

Abstract: A respiratory mask includes a mask body with a perimeter. The mask has a use position wherein the mask body covers at least the mouth and nose and the perimeter is in contact with the face surrounding at least the mouth and nose. At least one ultrasonic sensor is supported on the mask body in detecting proximity to the perimeter. The ultrasonic sensor is operable to detect ultrasound. The ultrasonic sensor allows leakage around the perimeter of the mask body to be detected.

Abstract: Provided is a device for use in locating the origin of a phenomenon of interest, including a sensor capable of detecting the presence of the phenomenon of interest and generating a detection signal in response thereto. The device also includes a phenomenon origin locator to monitor the detection signal and project light toward the origin when the detection signal satisfies a selected criteria level, thereby indicating the origin of the phenomenon of interest.

Abstract: In accordance with an embodiment, a gas turbine engine is provided having a bearing chamber leak detection system. The gas turbine engine includes a rotatable shaft, a bearing assembly supporting the rotatable shaft, and a plurality of bearing chamber seals surrounding the rotatable shaft creating an annular bearing chamber enclosing the bearing assembly. One or more walls substantially surrounding the bearing chamber create a plenum between the walls and the bearing chamber, and a pressurized air inlet to the plenum is provided. The pressurized air inlet includes an airflow sensor configured and positioned to sense a flow of pressurized air into the plenum, such that airflow at the sensor is indicative of airflow from the plenum into the bearing chamber via one or more of the plurality of bearing chamber seals.