Abstract: A leak detection system determines whether a container has a leak or an aperture by attempting to draw a vacuum in the container and determining whether a vacuum has been created in the container. If a vacuum can be created in a container, this indicates that the container has a leak. Conversely if a vacuum cannot be created in the container, this indicates that the container does not have a leak. The leak detection system preferably includes a conveyor system for moving a container and a sensor for sensing the pressure in the interior of the container through an opening in the top of the container. While the sensor is sensing the pressure in the interior of the container, a vacuum pump pulls air from the region around the exterior of the container. If the container has an aperture, a vacuum will be created in the container and will be noted by the sensor.

Abstract: A system, container, and methods are provided for containing and handling a toxic gas. The system preferably includes a first container having toxic gas stored therein and a second container including a base and a lid mounted to the base when in a closed position thereby forming an interstitial space therebetween, which base and lid are sealed against leaks out of the second container by a sealing material that may visibly indicates leaks by visibly changing color in response to contact with any toxic gas that has leaked into the interstitial space, or which container system may include a toxic gas sensor or pressure sensor for detecting presence of leakage gas within the interstitial space. The base has an inner chamber formed therein, and the first container is preferably mounted in the inner chamber so that an interstitial space is formed around at least portions of the first container.

Abstract: An apparatus for testing watertightness of a railcar comprises a blower fan apparatus with an exhaust duct and an exhaust outlet that can be sealed against an aperture in the railcar. The fan blower of the apparatus is capable of providing an airflow to the railcar to provide a pressure differential of between about 0.5 to about 2.5 inches of H.sub.2 O between an interior of the railcar and an exterior of the railcar. The blower is operated to provide air to the railcar to provide a pressure differential, causing bubbles to form in a liquid solution applied to the exterior surface of the railcar. The railcar is marked for subsequent repair at locations where bubbles are detected.

Abstract: A leak detection system and method for detecting leaks from a storage system containing a liquid, the leak detection method includes mixing one or more tracers soluble in the liquid to provide a liquid-tracer mixture within the storage system. The tracer provides a detectable component in the liquid-tracer mixture if the liquid-tracer mixture escapes the storage system through a leak. A subsurface sampling device is positioned near the storage system. The sampling device contains an adsorption material for adsorbing tracer from the liquid-tracer mixture that leaks from the system. The adsorption material is a hydrophobic, porous material. In one embodiment, a plurality of sampling devices are contained within a plurality of subsurface monitoring wells positioned around the storage system.

Abstract: A method and device for testing containers, the method calling for a difference in pressure to be generated between the pressure inside the container and the pressure immediately surrounding the container, the behavior of one of these pressures permitting the gas tightness of the container to be assessed. A pressure value is stored and subsequently compared with one of the pressures, the stored pressure value being stored electronically and compared with at least one value of the output signal from a pressure sensor. The container is housed in an enclosure which is connected to a pressure or suction line, and a pressure-value storage unit, a comparator unit and a pressure sensor are associated with the pressure or suction line.

Abstract: A protection system for hydraulic systems, mainly for pipes, faucets, valves, boilers, furnaces, etc.

Abstract: By referencing either liquid volume or liquid pressure to liquid temperature, either in an implicit way and mechanically or in a non-implicit way and metronomically, the development of an electrical fault or loss of liquid can be detected. The present invention is based on the principle that any deviation from the relation between temperature and volume of a liquid, or, by implication, temperature and pressure in that liquid--the latter relation being applicable to closed systems only--is indicative either of an electrical fault in the transformer or of liquid loss from the transformer.

Abstract: The invention is directed to an arrangement for checking the tightness of a vessel such as a tank system of a motor vehicle. The vessel can have a possible leak and this can be viewed as a first flow resistor. The arrangement includes a pressure source for generating a pressure change in the vessel and a pressure divider system is connected between the pressure source and the vessel which is subjected to the pressure change. The pressure divider system is defined by and includes the first flow resistor and a reference branch having a predetermined second flow resistor. A pressure sensor measures the pressure relationships in the pressure divider system. The invention provides a reliable statement as to a possible leak in the tank system of a motor vehicle while providing a simple and therefore cost effective manufacture. The pressure source used to check the tightness can be utilized for other tasks required in a motor vehicle. The invention also relates to a method for checking the tightness of the vessel.

Abstract: The method comprising measuring the rate at which working fluid is expelled from a cavity through a central tubing to a well head under atmospheric pressure at the well head; determining the shape of a zone of the well selected for positioning an interface between a test fluid and the working fluid; performing temperature measurements and pressure measurements over the full height of a cavity under atmospheric pressure at the well head; injecting additional working fluid into the central tubing or into the annular space until a predetermined test pressure is reached; measuring the compressibility of a cavity during the preceding step; injecting test fluid into the annular; measuring the depth of the interface between the test fluid and the working fluid for a first time at the end of injecting test fluid; measuring the test fluid and the working fluid pressures at the well head; measuring the level of the interface between the test fluid and the working fluid for a second time; and evaluating the real leakage

Abstract: A method for thermal volume modeling of the pipe fluid volume change by taking temperature change measurements of pipe fluid taken at a single location, and comparing it to the changes in the fluid volume inside a tank hydraulically connected to a said pipe; a method of determining a fluid leak by comparing a calculated fluid volume inside a tank(s) and the actually measured tank fluid volume, where calculations are based on the method.

Abstract: A vessel such as a dairy pasteuriser having a path B for product and a separate path A for coolant in intimate relationship is tested for leaks by circulating a donor fluid under pressure in path A whilst a recipient fluid such as clean tap water is circulated in path B. If the donor fluid is an electrolyte, a probe (12) is placed in path B to measure the conductivity of the recipient fluid. A rise in conductivity over a period indicates leakage between the two paths, the rate of change indicating the size of the leak. Alternatively, the donor fluid can be a gas, and leakage detected using an untrasound probe.

Abstract: A leakage testing apparatus for testing whether or not a hollow member of a hollow shape has a leakage, comprising: a hold mechanism for holding the hollow member such that the inside and the outside are isolated gas-tight from each other; an injection mechanism for injecting a testing gas into the hollow member held by the hold mechanism; and a leakage detector for sucking the gas around the hollow member held by the hold mechanism, to detect the leakage on the basis of the concentration of the testing gas in the sucked gas.

Abstract: An ultrasonic detector of the present invention includes an ultrasonic transducer for detecting ultrasonic energy and generating an electrical signal having an amplitude corresponding to the detected level of the received ultrasonic energy, and a light source supported in proximity to the ultrasonic transducer for illuminating an area from which the ultrasonic transducer may detect ultrasonic energy. Preferably, the light source is a directional light source positioned such that an optical axis of a light beam emitted from the light source intersects a directional axis of the ultrasonic transducer at a predetermined distance from the ultrasonic transducer. The ultrasonic detector of the present invention also preferably includes an indicator light coupled to the ultrasonic transducer for receiving the electrical signal output from the transducer and for indicating the relative amplitude of ultrasonic energy received by the transducer.

Abstract: A capacitor bank leak sensor apparatus for preventing damage or failure of the capacitor bank of the type which includes a plurality or array of spaced apart dielectric liquid filled capacitors positioned within a housing. The failure prediction/prevention apparatus includes a collecting tray or trough positioned within the housing and below the capacitors which is adapted in size and shape to catch and collect all dielectric liquid which leaks from any of the capacitors. All leaked liquid dielectric is drained into a container of a sensor device which activates viewable and/or audible indicia when a predetermined quantity of dielectric liquid has been collected in the container, the predetermined quantity preferably being less than that which would likely result in failure of one of the leaking capacitors.

Abstract: This invention relates to a leak tester for testing the tightness of a test object such as a fuel feed apparatus for an internal combustion engine, and specifically to a leak tester for testing the air tightness of a fuel feed apparatus provided with a first opening and a second opening and having a space portion between the first and second openings.

Abstract: A method and apparatus for testing watertightness of a railcar comprises a blower fan apparatus with an exhaust duct and an exhaust outlet that can be sealed against an aperture in the railcar. The fan blower of the apparatus is capable of providing an airflow to the railcar to provide a pressure differential of between about 0.5 to about 2.5 inches of H.sub.2 O between an interior of the railcar and an exterior of the railcar. The blower is operated to provide air to the railcar to provide a pressure differential, causing bubbles to form in a liquid solution applied to the exterior surface of the railcar. The railcar is marked for subsequent repair at locations where bubbles are detected.

Abstract: An apparatus for detecting a leak in the storage tank which includes a transducer for detecting and converting a mechanical wave into an electrical signal, a support tube having an upper end extending outside of the tank and a lower end extending inside the tank into the fluid medium. The transducer is affixed to the lower end of the support tube. A signal processing unit for processing the electrical signal, and electrical cable for transmitting the electrical signal from the transducer to the signal processing unit is also present. A method of using the apparatus is also provided.

Abstract: A leak detection system and method for detecting leaks from a storage system containing a liquid, the leak detection method includes mixing one or more tracers soluble in the liquid to provide a liquid-tracer mixture within the storage system. The tracer provides a detectable component in the liquid-tracer mixture if the liquid-tracer mixture escapes the storage system through a leak. A subsurface sampling device is positioned near the storage system. The sampling device contains an adsorption material for adsorbing tracer from the liquid-tracer mixture that leaks from the system. The adsorption material is a hydrophobic, porous material. In one embodiment, a plurality of sampling devices are contained within a plurality of subsurface monitoring wells positioned around the storage system.

Abstract: A method of checking the volume of containers is disclosed according to which a gas is fed into a volume which is correlated to the volume of the respective container and a signal which depends from the fed amount of gas is evaluated as signal indicative of the volume of the container. In order to substantially reduce the time of the measuring cycle at such a method a gas is fed to the volume which is correlated to the volume of the container at a controlled flow, i.e. the mass flow of the gas per unit of time is pre-set in a controlled manner such that it is possible to drastically reduce the time spans during which it is necessary to wait due to transient processes and a chamber which must be loaded in advance will become superfluous.

Abstract: A leak detector apparatus 10 is disclosed which measures changes in fluid level in a tube 54 substantially located within a reservoir 29 of hydraulic fluid. The tube 54 has a first end which is open to the atmosphere and a second end which is submerged in the hydraulic fluid. The reservoir 29 is selectively sealed, therefore changes in the volume of the fluid within the reservoir 29 cause the fluid level within the tube 54 to change in accordance with the principles of a manometer. A measuring device is utilized to determine the level of the fluid within the tube 54, wherein the measurement device can include a float 22 having a magnet 23 located thereon interacting with a linear array of Hall effect sensors 24. A controllable venting valve 28 is provided through the reservoir 29 to equalize the pressure within the tank with the external ambient pressure.

Abstract: A swimming pool leak detecting device including an interior housing slidable along a floor and side walls of a swimming pool. A telescopic pole is pivotally coupled with the interior housing. A floating housing is adapted to float on a surface of the swimming pool. The floating housing holds a predetermined amount of water therein. A hose is provided having an upper end fluidly coupled with the floating housing and a lower end fluidly coupled with the interior housing. A leak in the swimming pool will cause the water level in the floating housing to decrease. Sealant can be poured through the floating hosing and directed through the hose to the interior housing in order to seal the leak.

Abstract: A female-molded double-walled underground storage tank is provided with an annulus of reduced thickness, defined by a plastic film. The film separates the inner and outer walls of the tank, providing an annulus which can be monitored to monitor the tank for failure of either the inner or the outer tank, before contamination of the exterior environment. The tank is formed of fiberglass reinforced plastic, the inner and outer walls thereof being tied together by fiberglass reinforced plastic which holds the annular film in place. The domes of the outer and inner shell are separated due to a layer of wax and alcohol applied to the inner surface of the dome of the exterior tank prior to formation of the interior tank. The spaces between the flats of the two tanks, the domes of the two tanks, and the interior of the ribs of the exterior tank are placed in fluid communication by gutters running along the length of the tank.

Abstract: Disclosed an electro-optical sensor which preferably is used to detect leaks in marine surface and submarine anti-pollution hoses which are used to transfer petroleum products to and from ships. The electro-optical sensor is located in housings that allow petroleum products of varying viscosity's to flow to the sensor. A variety of alarm methods can be used to signal that a leak has occurred in the hose.

Abstract: A waterproof connector is checked for waterproofness, which waterproof connector has a terminal-accommodating chamber into which a terminal is inserted and which is sealed with a waterproofing rubber stopper through which an insulated wire attached to the terminal passes. A connector-holding block of a waterproofness-checking jig engages in a watertight manner with the connector-fitting side of the waterproof connector, followed by depressurizing the waterproof connector with an ejector and comparing the pressure inside the waterproof connector with a reference pressure to determine the presence or non-presence of a leakage. Owing to the depressurization of the waterproof connector, the terminal, if inserted incomplete, is moved into a fully-inserted position in the connector housing in one piece with the waterproofing rubber stopper. A waterproof connector can be easily and reliably checked for waterproofness without making errors, while remedying incomplete insertion of a terminal.

Abstract: An aboveground storage tank is provided with a mass balance system for quantitative detection of leakage of liquid from a tank. Arrays of temperature sensors measure the exterior wall temperature of the tank and temperature sensors in an open-ended standpipe within the tank measure the temperature of stored liquid. The temperature measurements and measurements of liquid level change in a chamber mounted at the upper end of the standpipe are polled at intervals to detect changes of the mass of liquid within the tank.

Abstract: A device for detecting leakage of fuel vapor including a pressure sensor which is arranged in a fuel vapor conduit connected to the fuel tank. The pressure sensor detects the pressure inside the fuel tank. It is judged that the fuel vapor has not leaked from the fuel tank or the fuel vapor conduit before the engine is stopped based on the pressure inside the fuel tank detected by the pressure sensor and it is judged that the reattachment of the fuel cap has been forgotten when it is judged that the fuel vapor is leaking from the fuel tank when the operation of the engine is restarted after stopping of the engine.

Abstract: A fluid leak detector mechanism having a main fluid tank, an expansion tank for receiving fluid therefrom as the fluid becomes heated and expands, and a sensing chamber operatively coupled with the main tank. A signalling mechanism signals to an operator when the level of fluid in the sensing chamber has dropped significantly to alert the operator of the presence of a leak. An oil return valve is operatively coupled between the main tank and the expansion tank and has an open position that allows fluid to flow back to the main tank from the expansion tank and a closed position that blocks oil from flowing from the expansion tank to the main tank. A temperature sensor senses the temperature of fluid. A control mechanism shifts the oil return valve to its open position when the temperature sensor detects a significant drop in fluid temperature, thereby allowing the fluid levels to be reset with changes in fluid temperature.

Abstract: A method of testing the leakage rates from tanks for containing volatile liquids such as petrol or diesel, with a view to determining whether the tank leaks excessively. The tank is at least partially filled during testing in order to save time. The leakage is detected by sealing the tank and measuring the drop in pressure in the tank over a period of time. In order to measure the rate of leakage, a first measurement is taken during which an amount of 380 ml is removed from the tank over a short period whilst otherwise sealed, with the resultant pressure drop being measured as a calibrated value. The tank is then re-sealed and the pressure drop over the period of an hour is compared with the calibrated value.

Abstract: An apparatus and method are provided for calibrating a liquid storage tank. The apparatus includes a sensor disposed within the tank for sensing the liquid levels in the tank and one or more metering devices for measuring the amount of liquid dispensed into or out of the tank. A processor is also provided which is capable of determining the volume in the tank as well as the amount of liquid dispensed into or out of the tank based on liquid level measurements obtained during idle periods following dispensing periods. The processor is programmed with an algorithm which employs a mathematical function which relates either the volume of the liquid or the change in volume of the liquid per unit of associated height change of the liquid in the tank as a function of the height of the liquid in the tank and a number of calibration parameters which include the length, diameter, end shape, and tilt of the tank as well as the offset of the sensor from the bottom of the tank.

Abstract: A system for detecting the position of a break in a water-barrier sheet placed in a waste disposal facility for isolating wastes from the ground of the waste disposal facility includes at least one optical fiber laid in a predetermined pattern between the ground of the waste disposal facility and the water-barrier sheet and constituting a temperature sensor capable of detecting a change in temperature caused when it is flooded with leakage water flowing out from a break in the water-barrier sheet at a temperature elevated under the effect of heat generated during biodegradation of the organic substances contained in the wastes, and a temperature measuring instrument connected to said optical fiber for detecting the position of the break in the water-barrier sheet via detection of the temperature change by said temperature sensor composed of said optical fiber.

Abstract: An improved liquid pressure measuring system comprising a container containing a liquid at a level to be sensed, a pressure sensing chamber located within said container and having an open bottom, a pressure sensing device connected to sense the pressure in said chamber, and means for generating gas within said chamber to balance the hydrostatic pressure of said liquid.

Abstract: A drain tank for installation underground has a longer life than steel and fibreglass tanks and has a leak detection system to identify leaks. The drain tank comprises a sealed concrete chamber having at least one opening at the top thereof with a collar integral therewith, a manway connected to the collar extending upwards, the manway having a top lid with a vent and pump out exit. Inside the concrete chamber is an impervious bag liner which is sealed to the collar; an entry pipe passes through the chamber side wall and the liner and a leak detector tube passes down into the chamber to a location at the base between the chamber and the liner having an intermediate gap spacing arranged therein for an insertion tube to pass therethrough thereby facilitating the task of leak detection when interconnecting such insertion tube with a vacuum means and a suction reservoir.

Abstract: A fluid drip detection system which is not prone to false alarms caused by the presence of dirt or solid particle contaminants in the fluid. The fluid drip detector comprises; a conducting hollow housing for permitting fluid flow and passage therethrough, the housing having a first and second conducting seats. A first conducting door is urged against the first seat and a second conducting door is urged against the second seat. The first and second doors disengage from their respective seats in a drip condition and in response to fluid movement. A conducting rod is connected to one of the doors and is slidingly fitted into a bore in the other door, such that in a no drip condition, if one of the doors is disengaged from its seat by dirt, the other door can still engage its seat, and a lead connected to the housing, for producing an electrical output in the event of a drip. Such electrical output is transmitted to a timer unit that can control the fluid flow by controlling a cut off valve.

Abstract: An acceleration responsive device 30 includes a support 34 which supports a rod 46 between two spaced portions of the support. A weighted disc 48 is mounted for movement on the rod and is held by a spring 128 at one end of the rod 46. An indicator 50 is also mounted for movement on the rod 46 adjacent disc 48. A tube 62 is coupled to support 34 to facilitate swinging movement of the device 30 where, due to the acceleration thereof, disc 48 is moved along rod 46 and pushes indicator 50 along the rod. When the swinging movement ceases, disc 48 is returned to the one end of rod 46 and indicator 50 remains at the position to which it was moved. A scale reading of a decal 89 adjacent the moved indicator 50 provides a indication of the acceleration attained during the swinging of device 30. This reading can be applied to a graph to assist the user of device 30 in the selection of golf clubs having a shaft stiffness most appropriate for the user.

Abstract: A portable emissions test apparatus for testing for vapor emitting leaks in a fuel holding system in a vehicle includes a pressurizing system and a pressure-monitoring system. The pressurizing system includes a first pressure regulator configured for connection to a source of pressurized gas for regulating a maximum first pressure in the apparatus downstream of the first pressure regulator, and a first surge protector connected to the first pressure regulator for controlling first surges from the first pressure regulator. The pressurizing system further includes an adjustable second pressure regulator operably connected to the first surge protector for adjustably regulating a second pressure of pressurized gas for operating the apparatus, the second pressure regulator including an adjustment knob positioned in a readily accessible position on the apparatus so that the pressure downstream of the second pressure regulator can be adjusted for changes in ambient atmospheric pressure.

Abstract: A apparatus and method of detecting a leak in an evaporative emissions system measures vapor flow out of the evaporative emissions system while maintaining a zero pressure difference from inside a fuel tank to atmosphere and provides a reference vapor flow variable dependent on the measurement (317). A pressurized vapor and leak flow variable is measured (323) dependent on measured vapor flow out of the evaporative emissions system while maintaining a pressure difference of 10" of water from inside the fuel tank to atmosphere. A leak is indicated (327) if a difference between the reference vapor flow variable and the pressurized vapor and leak flow variable is greater than a predetermined leak flow factor.

Abstract: An electric resistance measuring device situated in fluids, comprising; a housing having a bore therethrough, the bore having a seat; a movable door means situated in the bore, engagable with the seat; whereby, fluid movement disengages the door from the seat, changing the electrical resistance between the seat and the door. Such a device can detect leaks which increase the electrical resistance between the seat and the door. A panel provides selector means which can be set at different modes, each mode providing a different period of time in which fluid can be used continuously without interruption. If fluid movement exists after such period, a cut off valve will shut off the fluid. Such a device can be installed in line with fire sprinklers, such that the device will detect a fire and will send a signal to a central station.

Abstract: To measure the leakage rate in hollow bodies, the throughflow rate of the air flowing into the leaky hollow body is automatically measured and indicated numerically at a given test pressure. This is achieved by feeding fluid from a prechamber filled with fluid under measuring pressure to two measuring chambers (4,5) equipped with a testpiece and reference housing and having an identical cavity. The pressure decrease in a prechamber (1) is thereupon evaluated as a measure of the accessible volume in the two measuring chambers (4,5) and is compared with the volume given as permissible. If the measured accessible volume is higher than the volume given by the size of the chamber, the testpiece is qualified as highly leaky. If the volumes in the two chambers (4,5) correspond to one another, the chambers (4,5) are separated from the prechamber and the pressure difference between the chambers (4,5) and its trend in time are detected, in order to determine from this a measure of the tightness of the testpiece.

Abstract: A method of detecting leaks in a forced air furnace heat exchanger combustion chamber wall burning a blue color flame of gas includes introducing a fine mist of a liquid fire retardant compound into the return air stream upstream from a blower forcing air across the wall of the combustion chamber. Any change in the blue color of the flame toward an orange color indicates a gas leak through the combustion chamber wall.

Abstract: A double wall ribbed storage tank system is provided with the capability of independent monitoring of support rib areas and secondary containment areas of the tank system. The storage tank system comprises (a) an inner storage tank for primary containment of stored liquid with a set of support ribs for strengthening purposes, (b) an outer wall over the inner tank for secondary containment of the stored liquid, (c) rib communication means connecting together the support rib areas, (d) wall communication means connecting together secondary containment areas of the inner storage tank and outer wall, and (e) a monitoring station operably associated with the rib and wall communication means. Any structural damage to a support rib, inner storage tank wall or outer wall is detectable and generally located by the monitoring station.

Abstract: The present invention includes a device and a method for testing a can for leakage with the device including a main body, a mechanism for sealing against an internal surface of the can to effect a sealed chamber within the can, a mechanism for placing the mechanism for sealing in a sealing relationship with the internal surface of the can to effect the sealed chamber, and a mechanism for effecting an increase of pressure in the sealed chamber for determining leakage from the sealed chamber.

Abstract: In an arrangement for testing air-tightness of an electric device having an enclosed housing, and an electric connector fitted into an opening provided in the housing, the electric connector is provided with a communication hole for communicating the interior of the electric device with the exterior, and the communication hole is adapted to close when two halves of the connector are coupled with each other. Thus, the air-tightness of electric device can be conducted when the assembly work is substantially finished whereas the conventional arrangements require an additional assembly work step which could be a potential cause for loss of air tightness. Furthermore, the present invention can be implemented simply by providing a small communication hole in the electric connector and an associated sealing arrangement without requiring any change to the existing device to be tested.

Abstract: Bottles made of transparent plastic material or glass are subjected to at least one stationary examination device and further for detecting impurities or damage to the bottom, side wall or mouth regions of vessels. To be able to detect defects which may cause the bottles to leak, and which cannot be detected reliably by optoelectronic devices, the vessels are inspected additionally using a leak test by developing pressures.

Abstract: A system is provided for containing material leaks which occur while a shipping container is being loaded or unloaded. The system includes portable dome that is placed on top of a shipping container, covering the container's inlet or outlet valves. If a leak is detected, the flow of material is stopped, and the leaked material is either absorbed or neutralized.

Abstract: Systems for fluids (including liquids) and materials with a fluid phase. The material is confined in a primary containment, and a secondary containment is used to keep fluid leaking from the primary containment from the surrounding environs and to keep leachates and other fluids from the primary containment. A safe, non-toxic liquid in the interspace between the two containments is employed in detecting leaks in the containments and can also be employed to protect the containments against chemical attack.

Abstract: A unitized tank structure including a vessel having at least first and second compartments. Fill lines are coupled to the vessel providing access to fill the first and second compartments of the vessel. At least one sump riser portion is coupled to the vessel and extends therefrom. At least first and second dispensing lines are disposed within the sump riser portion and penetrate the vessel. Each dispensing line extends within the vessel and within the first and second compartments. Cross-over venting structure is provided within the vessel and is constructed and arranged to provide venting between the first and second compartments.

Abstract: An impoundment leak detection, location, and containment system comprises an impermeable grid having a plurality of leak detection modules positioned below the impoundment. A tunnel is located adjacent the impermeable grid, and a plurality of conduits provide fluid communication between each of the leak detection modules and the tunnel. Fluid leaking from the impoundment accumulates in the leak detection module directly below the leak and flows through the associated conduit where it is detected by a fluid sensor. The location of the leak is determined based on the known location of the leak detection module accumulating fluid.

Abstract: A solid state temperature compensated annunciator is disclosed. The solid state temperature compensated annunciator includes a pressure sensor for measuring a pressure of the fillant within a vessel and a temperature sensor for measuring the temperature of the fillant within the vessel. The solid state temperature compensated annunciator determines a pressure that the vessel would have if the vessel were filled with a predetermined amount of fillant, and compares the measured pressure to the determined pressure. If the measured pressure is below the determined pressure, a warning signal is issued.

Abstract: The present invention is directed to methods and apparatus relating to an accelerometer electrical signal recorder and playback module. The recorder module may be manufactured in lightweight configuration and includes analog memory components to store data. Signal conditioning circuitry is incorporated into the module so that signals may be connected directly from the accelerometer to the recorder module. A battery pack may be included for powering both the module and the accelerometer. Timing circuitry is included to control the time duration within which data is recorded or played back so as to avoid overloading the analog memory components. Multiple accelerometer signal recordings may be taken simultaneously without analog to digital circuits, multiplexing circuitry or software to compensate for the effects of multiplexing the signals.

Abstract: Apparatus for monitoring an externally applied parameter to selected products. The invention involves a housing enclosing a sensor, and a monitoring and output network. The sensor has a characteristic that varies in some predetermined manner with variation in the monitored parameter. The monitoring and output network involves a sensor which produces a signal representative of the monitored characteristic. Values associated with the signal are stored in a memory device for subsequent, selected retrieval.