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: A leak diagnostic system for a vehicle comprises a tank pressure module and a leak diagnostic module. The tank pressure module selectively outputs first and second fuel tank pressures when an engine is shut down and when engine vacuum is greater than a predetermined engine vacuum, respectively. The leak diagnostic module selectively diagnoses a leak in a fuel vapor purge valve based on the second fuel tank pressure when the first fuel tank pressure is less than a first predetermined pressure.

Abstract: A hermeticity sensor for a device includes a beam positioned within a substantially hermetically sealed cavity. The beam includes a stress that changes in response to being exposed to ambient from outside the cavity. A related method is also provided.

Abstract: A leak detector comprising a base appliance provided with a gas detector, a vacuum pump, and a control device. A sniffer probe is connected to the base appliance. A test leak device containing the supply of test gas is arranged in a separate sub-housing. The sub-housing also contains a temperature sensor, a processor, and a data memory. The processor corrects the measured temperature according to a sample, and modulates the light of a light barrier. The processor is connected to the control device in the base appliance by a data cable.

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 geological gas storage system and a method of detecting gas leakage from the geological gas storage system by using pressure monitoring, the geological gas storage system including: a formation structure including a reservoir formed of a permeable rock material in deep onshore/offshore formations, an impermeable cap rock layer formed above the reservoir, and an upper permeable formation formed of a permeable rock material above the cap rock layer; a hollow casing inserted in inner walls of the gas injection well bored from the ground to the reservoir and including a portion disposed at the same depth as a depth of the reservoir in which a plurality of gas injection holes are perforated in a circumferential direction of the casing; and a pressure sensor disposed at the same depth as a depth of the upper permeable formation and detecting pressure of the upper permeable formation.

Abstract: The invention relates to a device for controlling leaks from an endoscope, connected to the operating segment at the proximal end of the endoscope. The invention is characterised in that it comprises: a connection valve (2) for connecting the device to the endoscope (1), said valve being connected to the end of a tubular external housing (3), the opposite end of which housing is provided with an internal piston (4), also tubular, the size and shape of which are such that it moves in a sealed manner inside the housing in a direction parallel to the axis (5) of rotation of the housing (3) and the actual piston (4), said piston (4) having a test line (7) perpendicular to the axis (5) of rotation thereof.

Abstract: Apparatus for estimating a magnitude of leakage from a surgical tourniquet system while pressure in a cuff of the system is regulated near a reference pressure.

Abstract: A flowmeter is provided with a solid-state sensor technology for increasing the accuracy and efficiency of fluid flow monitoring and leak detection in the irrigation industry and other cost-sensitive flow-critical applications. The device can monitor and detect usage of fluids such as water more accurately and economically than presently possible to help eliminate waste and ensure correct billing. Measurement can be over an optimized narrow range or can be automatically switched to cover consecutive ranges from leakage to gross fluid conduit faults. With its minimal component count, ease of assembly, independence from the specifics of its housing, low maintenance needs, and its interchangeability this device can serve a wide range of metering needs from low end leak monitoring to standard flow measurement.

Abstract: Systems and methods for performing leak testing on fuel system components in hybrid vehicles during engine-off operating conditions are disclosed. For example, a fuel tank may include a pressure accumulator which may be filled with fuel via a fuel pump in order to generate a vacuum which may be used to diagnose leaks in the fuel system.

Abstract: Disclosed is a method for detecting a leak gas in a flushing device (10), comprising the following steps: the flushing device (10) is disposed on a part (201) that is to be tested; a flushing gas is conducted through the flushing device (10); and the leak gas is detected in the flushing gas that is discharged from the flushing device (10) with the aid of a detector device (30). In order to conduct the flushing gas through the flushing device (10), a predetermined main flushing gas flow (QH) is generated, and said main flow (QH) is separated into a system flow (QS) and a partial flow (QT) on a dividing device (40), the system flow (QS) being fed into the flushing device (10). Also disclosed is a leak testing apparatus (100) for detecting a leak gas in a flushing device (10).

Abstract: A water leakage monitoring system including a water leakage position estimator which includes a periodic data acquiring unit for fetching predetermined-period flow rate pressure data stored in a monitoring device, and for fetching a signal related to a flow rate change and pressure changes expecting a water leakage reaction time calculating unit for calculating a pressure reaction time lag between two pressure changes, a pressure propagation velocity estimating unit for estimating a pressure propagation velocity using the pressure reaction time lag and a distance between two pressure gauges located in a water distribution block stored in a pipeline network map data, and a flow rate change position estimating unit for receiving a signal related to the flow rate change, and estimating a flow rate change position using pressure propagation velocity and a flow meter and pressure gauge locating positions of the pipeline network map data.

Abstract: Disclosed are a method of detecting a leak of fluoroolefin compositions and sensors used therefor. In particular, the method is particularly useful for detecting a leak of a fluoroolefin refrigerant composition from a cooling system of an automotive vehicle. Such fluoroolefin refrigerant compositions have double bond structures which make them particularly well suited with sensing technologies, including: infrared sensors, UV sensors, NIR sensors, ion mobility or plasma chromatographs, gas chromatography, refractometry, mass spectroscopy, high temperature thick film sensors, thin film field effect sensors, pellistor sensors, Taguchi sensors and quartz microbalance sensors.

Abstract: An underground storage system includes a primary containment unit and a secondary containment unit arranged to sealingly encompass the primary containment unit. The underground storage system further includes a leak detection system which is fluidly connected to the secondary containment system, and which is adapted to detect fluid leaks in the primary containment system and the secondary containment system.

Abstract: A system and method for detecting small hydrogen leaks in an anode of a fuel cell system. The method includes determining that a shut-down sequence has begun, and if so, deplete the cathode side of a fuel cell stack of oxygen. The method then increases the pressure of the anode side of the fuel cell stack to a predetermined set-point, and monitors the pressure decay of the anode side of the stack. The method compares the rate of pressure decay to an expected pressure decay rate, and if the measured pressure decay rate exceeds the expected pressure decay rate by a certain threshold, determines that a potential leak exists.

Abstract: A method to amplify the pressure effects of very small flows, or very small leaks, in contained fluid systems, and the effects of small leaks in fluid systems that have small flows such as would occur in a combustible gas system with lighted pilot lights or a contained water system with a drip watering system, while not affecting the normal operation of such fluid systems, and without interfering with the function of such small flows.

Abstract: A refrigerant leak detection system is provided for a motor vehicle, in which the system includes a heating, ventilating, and air conditioning (HVAC) module having a refrigerant sensor assembly adapted to be fixed within the drain hole of the sump. The refrigerant sensor assembly includes an elongated sensor element extending into the sump, a flange portion having apertures that allows the condensate to drain from sump, a collar portion with self-tapping threads.

Abstract: A hydrocarbon presence sensor used to detect for the presence of a fuel in a buffer cavity of an inter-propellant seal. A sensor is formed on a rotor shaft in the buffer cavity and an optical imaging device is used to view a change in appearance of the sensor when a hydrocarbon forms on the surface. In one embodiment, the sensor is a coating of porous silicon. In other embodiments, the sensor can be a mirrored or frosted surface on the shaft. A white light source or a laser is reflected off of the sensor and an optical imaging device reads the reflected light to detect for a change in color or intensity of the light to indicate if a hydrocarbon is present on the sensor surface.

Abstract: Disclosed are a method of determining the components of a fluoroolefin composition, a method of recharging a fluid system in which the composition is used, and sensors used therefor. In particular, the composition may be a fluoroolefin refrigerant composition used within a vapor compression system, where the refrigerant composition is useful in cooling systems as replacements for existing refrigerants with higher global warming potential. Such fluoroolefin refrigerant compositions have double bond structures which make them particularly well suited with sensing technologies, including: infrared sensors, UV/vis sensors, NIR sensors, ion mobility or plasma chromatographs, gas chromatography, refractometry, mass spectroscopy, high temperature thick film sensors, thin film field effect sensors, pellistor sensors, Taguchi sensors and quartz microbalance sensors.

Abstract: A leak detection system for a flowing electrolyte battery comprising a containment member associated with at least one of a stack of a flowing electrolyte battery and an electrolyte reservoir of a flowing electrolyte battery and a sensing member for sensing a fluid leak within the containment member.

Abstract: The invention relates to an infusion device for therapeutic use comprising a water-tight cover in the form of a housing, a housing part or a receptacle for holding said infusion device and a control system which is used for controlling the cover water tightness and comprises c) a medium arranged in the cover and characterized by at least one physical or chemical quantity variable according to the cover water tightness and d) an information system which automatically transmits at least one information signal when said quantity changes in such a way that the loss of the cover water tightness is indicated.

Abstract: An apparatus for determining the integrity of an antenna system, including a controller, at least one valve operationally connected to the controller, a source of pressurized gas, at least one microwave antenna and a pressure sensor. The at least one microwave antenna is fluidly connected to the pressurized gas by way of the at least one valve. The pressure sensor is in communication with the controller. The pressure sensor senses the pressure of the pressurized gas. The controller is configured to check for a gas leak in the at least one microwave antenna by checking for a change in the pressure with the at least one valve being alternatively opened and closed.

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: An apparatus (10) for pressurising an aircraft cabin structure (12) and measuring the amount of leakage of the aircraft cabin structure (12) comprises an air supply line (14) which at a first end is connectable to a pressurized air source and which at a second end is connectable to the aircraft cabin structure (12) so as to supply pressurized air from the pressurized air source into the aircraft cabin structure (12), an air supply valve (36) disposed in the air supply line (14), a pressure sensor (50) for sensing the pressure inside the aircraft cabin structure (12) and for providing signals indicative of the pressure inside the aircraft cabin structure (12), an air discharge line (42) which at a first end is connectable to the aircraft cabin structure (12) an which at a second end is connectable to an air discharge opening (44) so as to discharge air from the inside of the cabin structure (12) to the air discharge opening (44), and an air discharge valve (48) disposed in the air discharge line (42).

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: Reference leakage device (1) for use in leakage detection of gas, comprises a membrane (5) adapted to be interposed between two environments having respective pressures pu and pa, where (I). The membrane has an orifice (6) adapted to determine a controlled gas flow depending on the pressure pu. The orifice has a preset diameter D and length L such that (II). The diameter D and the length L are further dimensioned in such a manner that the equivalent diameter De of the orifice is De?100 nm, where De is defined by the relation De=D.a1/2 wherein a is the transmission probability of the orifice, function of the L/D ratio. The orifice is adapted to operate in molecular flow regime in an entire range of p? values comprising the value of atmospheric pressure.

Abstract: A method and device for identifying leaks in or a leakage rate of an integrated circuit package. The method and device include integrating a micromachined-thermal-convection accelerometer in the integrated circuit package and evaluating the initial and subsequent sensitivities of the accelerometer. A change in sensitivity with time provides indicia of a leak and a measure of leakage rate.

Abstract: Improved respirator fit-test methods and apparatus featuring an automated, respirator wearer-controlled, air-leak measurement system. For fit testing of a respirator positioned on a test subject's face and connected to a controlled negative pressure testing apparatus, the test subject simply holds his breath and then activates a switch in electrical connection with said apparatus, which results in the automatic closure of the breathing port on the respirator and the initiation of a complete fit-testing protocol. The fit-testing apparatus includes a single, self-contained, automated unit that includes a vacuum source (30), an air-flow measuring device, and an air-pressure transducer (32) for connection to a respirator (10) being tested. By measuring the rate of air exhausted from the respirator in order to maintain a constant challenge pressure, an air leakage rate is determined.

Abstract: Provided is a leakage detection system and method using an image that may detect a leakage of high temperature high pressure steam using an image. The leakage detection method may include: obtaining an image of a target where a leakage of high temperature high pressure steam occurs; detecting, in the obtained image, an edge image before the leakage occurs and an edge image after the leakage occurs; detecting only a leakage edge image by comparing the edge image before the leakage occurs and the edge image after the leakage occurs; removing noise from the leakage edge image; and displaying the leakage edge image in which the noise is removed.

Abstract: The present invention relates to a method of assessing the condition of a duct along which a gas is flowing. The method comprises producing one or more sensor carrying elements, wherein the elements are formed to have selected parameters; introducing the sensor carrying elements into the flowing gas; and selecting the parameters of the sensor carrying elements such that the elements are transported along the duct by saltation. The present invention also relates to a method of reducing leakage through a leak in the duct.

Abstract: A test head (10) for breathing mask testing includes a hard head part (12) formed of a hard material and includes a face side (18) and a soft face front (14) of a defined thickness applied to the face side (18) of the hard head part (12). The soft face front (14) has a simulated human face surface defining a mask seal contact surface (22). A breathing mask testing system is also provided including the testing head (10) including a human face surface defining a mask seal contact surface (18) and a mouth opening connected to a respiration tube (50). A testing device (32) is provided with a test head adapter (30) protruding from the testing device (32). The hard head part (12) has a support portion (29) with an adapter interface for the adapter (30). The adapter interface includes a rotational position fixing mechanism for fixing the hard head part (10) to the adapter (30) in one of a plurality of rotational positions.

Abstract: A method of detecting a leak in a curing bladder during a tire curing process provides a curing bladder (40) and tire (42) in a tire mold structure (18). An inert tracer gas (48) is added to a pressurized gas such as nitrogen, with the nitrogen inflating the curing bladder so that the curing bladder engages a portion of the tire. The method detects whether the inert gas is present between the curing bladder and the tire while the curing bladder and tire remain in the tire mold structure. A curing bladder leak detection system (10) for a tire curing press (12) is also provided.

Abstract: According to one embodiment, a liquid leak sensing structure is provided with a casing including a lower wall, a circulation unit received in the casing and providing circulation of a liquid, a liquid leak sensor interposed between the lower wall of the casing and the circulation unit, and a liquid absorbing member interposed between the liquid leak sensor and the circulation unit. The liquid absorbing member permits part of a liquid from the circulation unit to flow therethrough toward the liquid leak sensor.

Abstract: The invention provides for a pressure-based tester for testing integrity of a platform assembly. The platform assembly includes a pair of assembled platform components fastened together and a fluid path extending into both components, the platform assembly suitable for supporting printhead integrated circuits to be tested. The tester includes a housing assembly, a regulated gas supply arranged in the housing assembly, and a retaining mechanism in fluid communication with the gas supply and configured to retain the platform assembly in fluid communication with the gas supply during testing of the platform assembly.

Abstract: A method for manufacturing an MEMS device is provided. The method includes steps of a) providing a first substrate having a concavity located thereon, b) providing a second substrate having a connecting area and an actuating area respectively located thereon, c) forming plural microstructures in the actuating area, d) mounting a conducting element in the connecting area and the actuating area, e) forming an insulating layer on the conducting element and f) connecting the first substrate to the connecting area to form the MEMS device. The concavity contains the plural microstructures.

Abstract: A leakage diagnosis apparatus for diagnosing presence/absence of refrigerant leakage in a refrigerant circuit performing a refrigeration cycle, wherein refrigerant leakage diagnosis using the amount of refrigerant exergy loss in a circuit component of the refrigerant circuit is realized. In a leakage diagnosis apparatus, an exergy calculation section calculates a leakage index value which changes in accordance with the amount of refrigerant leaking out of a refrigerant circuit based on the amount of refrigerant exergy loss in the circuit component. Then, a leakage determination section determines whether there is refrigerant leakage in the refrigerant circuit based on the leakage index value calculated by the exergy calculation section.

Abstract: A method and apparatus for monitoring and determining fuel vapor recovery performance is disclosed. The dispensing of liquid fuel into a tank by a conventional gas pump nozzle naturally displaces a mixture of air and fuel ullage vapor in the tank. These displaced vapors may be recovered at the dispensing point nozzle by a vapor recovery system. A properly functioning vapor recovery system recovers approximately one unit volume of vapor for every unit volume of dispensed liquid fuel. The ratio of recovered vapor to dispensed fuel is termed the A/L ratio, which should ideally be approximately equal to one (1). The A/L ratio, and thus the proper functioning of the vapor recovery system, may be determined by measuring liquid fuel flow and return vapor flow (using a vapor flow sensor) on a nozzle-by-nozzle basis. The disclosed methods and apparatus provide for the determination of A/L ratios for individual nozzles using a reduced number of vapor flow sensors.

Abstract: A method of discovering leakage in a heat exchanger, wherein the method is carried into effect on an intact heat exchanger which, together with surrounding conduits, is filled with water. The heat exchanger preferably has requisite pressure indicators mounted between each section, as well as requisite shut-off valves. The method comprises applying in each section of the heat exchanger an excess pressure on one side which is enclosed there, while the other side is at normal pressure. The pressure is enclosed during a period of time and is monitored during this period of time.

Abstract: Provided is a leak tester for a carrier for printhead integrated circuits. The carrier has at least one fluid inlet in fluid communication with a plurality of fluid outlets via discrete fluid paths. The tester includes a support assembly that includes at least one receptacle shaped and configured to receive at least one respective carrier, and a pressurized fluid supply arranged on the support assembly and configured to supply pressurized fluid to the fluid inlets, the pressurized fluid supply incorporating a sealing mechanism configured to engage the fluid inlets in a sealing manner.

Abstract: The gas sensor has a selectively permeable membrane which is composed of silicon material and is provided with a heating device on the outside. The membrane closes an evacuated housing which contains a pressure sensor. When evacuating the area surrounding the housing, the heat dissipation is changed as a result of the quick change in the total pressure of the surrounding air, with the result that signal drift arises despite temperature regulation of the membrane. The disclosure provides at least one second heating device whose temperature is regulated independently of the first heating device. As a result, the membrane temperature is highly constant even in the case of severely changing total pressure in the housing.

Abstract: An in situ reverse flow shipboard membrane integrity test apparatus and method, for determining if a membrane arrangement is defective. A membrane arrangement within a separation unit is tested when the membrane arrangement is arranged to perform wastewater separating functions. The separation unit includes a first inlet conduit, a first outlet conduit, and a second outlet conduit. An end cap is attached to the second outlet conduit to seal the second outlet conduit. A test air supply connected to the first outlet conduit for supplying an airflow to the membrane and a microparticle source containing microparticles for injecting microparticles into the airflow forming a test airflow. The test airflow is directed towards the membrane, and a filter is positioned over the first inlet conduit. The presence or absence of microparticles on the filter indicates whether or not the membrane arrangement is defective.

Abstract: A method and device for determining the hydraulic leakage rate of liquid-conveying parts, in particular injection valves for internal combustion engines, place the liquid-conveying part into a test body, and the liquid-conveying part is charged with a test liquid under a particular pressure, and a carrier gas stream is provided in a flow duct of the test body, and a vapor mixture behind the liquid-conveying part is conducted to an analyzer, and a measurement and analysis are carried out, using the analyzer, of the hydraulic leakage rate of the liquid-conveying part via the concentration of test liquid in the vapor mixture, the carrier gas stream being brought in via a nozzle element close to the leakage point of the liquid-conveying part, and/or a heating of the vapor mixture being provided behind the liquid-conveying part for complete conversion into the gas phase.

Abstract: A method for determining the amount of fuel flow from a high pressure gas tank to the anode side of a fuel cell stack through pulsed injector. The anode sub-system pressure is measured just before the injector pulse and just after injector pulse and a difference between the pressures is determined. The difference between the pressures, the volume of the anode sub-system, the ideal gas constant, the anode sub-system temperature, the fuel consumed from the reaction in the fuel cell stack during the injection event and the fuel cross-over through membranes in the fuel cells of the fuel cell stack are used to determine the amount of hydrogen gas injected by the injector.

Abstract: An apparatus for testing a protective mask. The apparatus includes a testing unit for testing a protective mask. The testing unit includes a headform upon which a protective mask to be tested is mounted. The testing unit is configured to take a sample of the challenge from two different locations about the protective mask. The testing unit may also be configured to inflate and deflate a neck seal protective mask when mounted on the headform prior to performing a mask leakage test to eliminate or significantly reduce pockets or folds that may hide a leak.

Abstract: A method for detecting and predicting total hydraulic fluid level for aircraft hydraulic systems includes determining an estimated value for a parameter indicative of total fluid level or mass. Each new value is combined with an historical indication (e.g., from previous flights) to provide a prediction for the future value of total quantity indication. With the same combination, one can provide an estimated value for total system leakage or level loss. An alert can be generated if hydraulic fluid level or mass is predicted to fall below a predetermined level.

Abstract: A tool for assisting the leak testing of an enclosed volume is disclosed. The tool may comprise an outer seal defining inside its perimeter an attachment face of the tool. A vacuum port defined in the attachment face is configured to be fluidly coupled to a vacuum source. A nozzle disposed in the attachment face may be coupled to the test port, in fluid communication with the enclosed volume. A primary connection in fluid connection with the nozzle may be placed in fluid connection with the external conduit. A nozzle seal is disposed in the attachment face around the perimeter of the nozzle, such that when the nozzle is coupled to the test port, the nozzle is fluidly isolated from said vacuum port. A leak-test system incorporating at least one tool and a method for leak testing an enclosed volume using the tool are disclosed.

Abstract: The present invention is directed to a waterproof electronic device with a test structure, including a test opening, a sealing structure and a fixation structure. The test opening is arranged on a housing of the waterproof electronic device, and is used for injecting a test fluid for detecting water leak. The sealing structure is arranged on the housing or a test fixture, and is used for holding a sealing element such that the waterproof electronic device and the test fixture may be sealed to each other when performing a leak test. The fixation structure is used for fixing the test fixture on the waterproof electronic device.

Abstract: An apparatus and method of sensing leakage of chemical liquid is provided. The apparatus for sensing leakage of chemical liquid, includes a sensing unit measuring a flow rate of chemical liquid being supplied to a process chamber, a process control unit judging whether leakage of the chemical liquid has occurred using the measured flow rate of the chemical liquid and generating a control signal, and an equipment control unit receiving an input of the control signal and controlling an operation of equipment.

Abstract: A method for detecting abnormality in a fluid supply line is provided that uses a fluid control apparatus with a pressure sensor so that abnormality of malfunction and sheet leaks of a plurality of valves incorporated into the fluid supply line can be checked easily, promptly and accurately by operating the flow rate control apparatus possessing the pressure sensor. Specifically, using a fluid supply line provided with the flow rate control apparatus possessing the pressure sensor equipped with a flow rate setting mechanism, a flow rate/pressure display mechanism, and/or a flow rate self-diagnosis mechanism, abnormality of the control valves, installed with the flow rate control apparatus and on the upstream side and downstream side thereof, is detected by using the pressure value displayed and/or the value diagnosed with a self-diagnosis mechanism of the flow rate control apparatus.

Abstract: A refrigerant leak detection system is herein disclosed. The system can detect the existence of a slow leak based on the refrigerant level and the system data. They system uses data models, either stored or dynamically created, to calculate an expected refrigerant level. Based on the expected refrigerant level and the actual refrigerant level and statistical process control data, a leak can be identified.