Abstract: In a hydraulic reservoir of a master cylinder for vehicle including: a main body having an internal space for storing brake fluid; a float provided with permanent magnet, so arranged as to be vertically movable in the internal space of the main body; a reed switch attached to the outside surface of the main body, the reed switch being actuated by magnetic force of the permanent magnet, when the float with permanent magnet is positioned under a predetermined level; and a hollow for attaching the reed switch to the outside surface of the main body, the reed switch is supported by a support member in the hollow, a rubber bush is tightly and elastically fitted to the inside wall of the hollow and a fixing member is so fitted to the hollow as to push the rubber bush to the support means, terminals of the reed switch being inserted tightly through holes of the rubber bush whereby the reed switch is held in the hollow.

Abstract: Liquid level sensor comprising a rod (2) on which a first (4) and a second (5) resistance wire are wound helically and parallel, a float (3) which is displaceable along the rod and which comprises a contact element which has a first (11) and a seond (12) contact plate, which each make contact with one of the resistance wires (4, 5) respectively, and a circuit which runs through the resistance wires and the contact element and whose resistivity varies depending on the position of hte float along the rod, in which respect the resistance wire (4) is recessed in the rod in the area in which the resistance wire (5) bears against the contact plate (12) while the resistance wire (5) is recessed in the rod in the area in which the resistance wire (4) bears against the contact plate.

Abstract: A pivoted float contains a solid-state inclinometer which produces sensitive electrical output responsive to angular displacement of the float from the direction of gravity. The float is capable of resolving very small changes in liquid level in a vessel, and thereby indicating or warning of small leaks from the vessel.

Abstract: In a screened inductance sensor having a drive winding, a sense winding, and a conductive screen for varying the induced voltage in the sense winding by reason of the eddy currents generated in the conductive screen in the presence of the drive field, a physical barrier is interposed between the region of the sensor in the windings are located and the region in which the screen is located. These regions are fully environmentally isolated from each other by the physical barrier. The construction is especially suited to screened inductance level gauges, in particular for fuel tanks, where the conductive screen is part of a float assembly in contact with the fuel, but the electrical windings are kept dry in a separate portion of the gauge.

Abstract: An alarm system is disclosed for use with a water softener including a salt-brine tank containing a bed of salt. The alarm system includes a sensor situated in the salt-brine tank on the top of the bed of salt, an electronic circuit including an alarm, and an input for connecting the circuit to the sensor. The sensor is responsive to direct contact with the brine for operating the circuit to initiate the alarm in the event the top of the bed of salt drops below a preselected level or the brine rises above another preselected level.

Abstract: A plurality of spaced reed switches vertically aligned for positioning in a liquid. Each of the reed switches vertically overlaps the adjacent above and below reed switches and the longitudinal axis of the reed switches is at an angle to the vertical. A float carries magnets and is movably positioned coaxially about the plurality of switches. An electrical indicator is connected to the switches for indicating the vertical position of the float relative to the switches.

Abstract: A cylindrical alarm-functioned accessory device for intravenous infusion procedure comprising a cylindrical body connected through a drip tube to receive fluid from a fluid bottle thereinto, an enclosed cylindrical float which senses the condition of a fluid pool formed in the cylindrical body, and a contact-type switch extending into the cylindrical body with connection to a sound and light alarm assembly. As the bottled fluid drains, the cylindrical float descends according to the descending of the fluid pool, pressing against the contact-type switch to activate the alarm assembly.

Abstract: An alarm kit for notifying a user of a noncommercial water purification system that the level of liquid with the chemical tank of the system is below a predetermined level includes a float, a housing, an alarm, an activation device and a connection member. This alarm kit can be easily installed by a homeowner or other user of the system and will allow the user to avoid complete depletion of the liquid from the chemical tank. The float either floats on top of the liquid or is submerged therein and will cause movement of the connection member when the liquid level drops below the predetermined level. The connection member will then pivot an arm of the activation device to cause the alarm to be activated in order for the user to be alerted that the liquid within the tank needs to be replaced. The predetermined level is determined by the usual rate of withdrawal of liquid from the tank and the usual time required to replenish the fluid, such as the response interval of a vendor to a request for service.

Abstract: A magnetic float for a magnetic sensor wherein magnetized magnetic powder is dispersed into a foamed synthetic resin, and the magnetic flux thereof acts on a reed switch in the magnetic sensor to turn on or off the reed switch. The magnetic powder is substantially wholly coated with the synthetic resin.

Abstract: A liquid float gage assembly for a fluid reservoir includes magnet containing float in a vertical tube having an adjacent vertically spaced reed switch arrangement. The float is capsule shaped with an extended round cylindrical portion having rounded axial ends; and the magnet tends to be attracted to the closest reed switch to bias the float against the inner surface of the tube. The tube has a horizontally cross-sectional shape substantially matching and just larger than an axial section of the float so that the float has a stable floating orientation with a horizontal axis and is capable of rolling during vertical movement within the tube to reduce friction due to liquid surface tension between the float and the tube. The magnet has poles at axially opposing ends thereof within the float and a circumferentially consistent spacing relative to the outer surface of the float so as to provide a substantially non-varying magnetic field strength radially adjacent the float as the float rolls.

Abstract: The position sensor of the present invention includes a pair of elongated conducting members disposed in a parallel arrangement and a conducting metallic ball or mercury drop freely movable following the pair of elongated conducting members while maintaining a simultaneous contact with the pair of elongated conducting members, which combination provides two electric circuits respectively including a first circuit including a first poriton of the two elongated conducting members and the contact provided by the metallic ball or mercury drop, and a second electric circuit including the second portion of the two elongated conducting members and the same contact, wherein the metallic ball or mercury drop divides the combination of the two elongated conducting members into the first and second portions.

Abstract: The gauge has an outer tube sealed at its lower end and adapted for attachment to the top wall of the tank. The gauge also has an inner tube axially movable within the outer tube. A float encircles the outer tube. Magnets respectively attach to the float and to the lower end of the inner tube, whereby a rising liquid causes the inner tube to rise as well. When the liquid level reaches a predetermined high level, a pencil-type magnet mounted within the inner tube operates a switch in an alarm box mounted in the top of the outer tube.

Abstract: A water level and temperature detector alarm device and more particularly to an alarm device which includes a buoy type detector to alternately detect water level or water temperature so as to provide an audio alarm signal through a buzzer when water level or water temperature reaches the predetermined range. The detector is connected to the expansible end of a conduit and includes a sleeve having set therein two reed switches and a thermswitch and having mounted thereon a body which includes therein a circular magnet. An alarm device is connected to the other end of the conduit which is having a movable positioning rack mounted thereon for positioning of the whole assembly. Following the rising of water level, the magnet of the buoy alternatively drives the reed switched to turn on the alarm device to buzz or, when water temperature reaches the predetermined range, the thermoswitch will be turned on to drive the alarm device to buzz.

Abstract: A gauge assembly (10) is disclosed which incorporates a voltage divider circuit to provide reliable and accurate measurement of a fluid level within a tank (16) or other environment. A pointer assembly (52) pivots about an axis (42) in response to a moving float to indicate the fluid level. A plurality of contact arms (92, 94, 96) extending from a contact plate (58) on the pointer assembly (52) resiliently engage a point (91) along a resistive element (84). The ends of the resistive element (84) form first and second contacts (86, 88) while the point (91) of contact between the contact arms and resistive element is connected to a third contact (90) to form a voltage divider circuit.

Abstract: The level indicated on the instrument panel of the motor vehicle results from a processing operation, including the calculation of a weighted average value, whereby the effects of accidental phenomena such as agitation of the fuel within the tank during movement of the motor vehicle are dispensed with.

Abstract: Multiple contact sensors located at axially spaced measurement zones, inside or outside of an elongated probe, closes a variable resistance circuit through the conducting substance being monitored, with monitoring means being a three-way or multicolored light emitting diode, which in connection with an AC power source and a transistor, changes color and luminosity as the substance being monitored reaches the various levels of the contact sensors.

Abstract: A display control apparatus for use in an internal combustion engine includes: a CDI type ignition circuit; an overspeed preventing circuit which can limit the engine speed to a restricted value; a first LED display unit of the light on/off type to display the amounts of oil and/or cooling water; a second LED display unit to display the circulation state of the oil and/or cooling water; and a drive circuit which switches the first and second display units to an alarm display mode and causes the overspeed preventing circuit to limit engine speed when abnormal states of the oil and/or cooling water are detected by oil level switches or by water and oil flow sensors. If power ceases, the display state is held by keep relays. When an abnormal state is detected, the driver is warned by lighting up of red LEDs and by generating a beeping sound from a buzzer.

Abstract: A signalling device for signalling danger from water over a low water crossing area is provided. The device has a support post, a message panel, and flashing lights in electrical connection with an energy source, the electrical connection being completed by triggering a switch lever by either a tank float rigidly mounted to a bottom end of a centrally disposed elongate guide member or by a donut-shaped tank float received about the elongate guide member and stopped by a stop member, either the rigidly mounted float pushing the elongate rod upwards and triggering the switch lever, or the donut shaped tank float and stop pushing the elongate rod upwards and triggering the switch lever.

Abstract: A liquid level control in a refrigeration system operates a solenoid valve to maintain the level of liquid refrigerant in a vessel within a range defined by predetermined lower and upper liquid levels, sounds an alarm if the upper level is exceeded and stops a pump if the lower level is violated. The control comprises a float assembly and a switching assembly. The float assembly comprises a float chamber connected to the vessel, a float ball therein, a vertically extending float rod connected to the float ball and movable along a vertical path, and a pair of spaced apart stop members on the float rod disposed within the switching assembly. The switching assembly comprises a switch actuator permanent magnet, having magnet poles at opposite ends, slidably mounted on the float rod between the stop members and movable thereby along the said path.

Abstract: A sensor for sensing the quantity of refrigerant in a closed loop refrigeration system, with the sensor having attachment means on a lower portion thereof such that it may be installed in direct communication with the refrigerant line of the refrigeration system. The sensor has a hollow interior portion defined by generally cylindrical sidewalls, in which interior portion a float of conductive material is disposed, with the float being free to rise on the surface of liquid refrigerant entering the interior of the sensor from the refrigerant line. At least one electrode is disposed in the interior of said sensor, in a position such that it will be contacted by the float at the time a certain refrigerant level is reached in the interior of the sensor.

Abstract: Apparatus for detecting the level of a liquid. A metal-detecting proximity sensor is placed near a non-metallic, vertically-positioned guide shaft. A float is placed on the liquid. A tube has one end attached to the float and the other end insertably placed within the guide shaft. A piece of metal is placed within the tube. When the apparatus is used for determining when the level of the liquid reaches a predetermined value, the metal piece has a boundary which is located at the height of the proximity sensor only when the liquid level is at its predetermined value. When the apparatus is used for measuring the level of the liquid, the proximity sensor has an output signal proportional to the distance from itself to metal and the metal piece has an outer surface whose distance to the proximity sensor at the height of the proximity sensor, changes with changes in the liquid level.

Abstract: The present invention provides an automatic cut off switch which grounds the magneto-spark plug circuit of a small gasoline engine shutting the engine down when the quantity of lubricating oil within the sump falls below a predetermined quantity. The switch is operated by a balance beam float assembly housed within a protective shroud. The protective shroud acts to collect a relatively stable pool of oil, representative of the quantity of oil remaining in the sump, for activation of the balance beam float. Upon refilling of the oil sump the switch automatically resets thereby permitting re-start of the engine.

Abstract: To improve the denseness of a reservoir telltale sounding device of a reservoir for a hydraulic brake system, while reducing the costs of manufacture and assembly, the plug portion comprises a first face and a second face which are respectively connected, in liquid-tight manner, to the housing of the reservoir telltale sounding device and the cover.

Abstract: An apparatus for checking the workability of a float assembly used to determine the level of liquid in a vessel is disclosed and comprises: a float extension associated with the float of the float assembly and movable when the float assembly is in working order in response to the movement of the float caused by changing the level of liquid in the vessel; a sensor located in spaced relation to the float extension and acting to provide a signal when the float extension is in a predetermined position; and a checking system capable of being activated to move the foat extension into the predetermined position without regard to the level of liquid in the vessel when the float assembly is workable.

Abstract: A combination hybrid float switch comprising float support means, float support means including a top and a bottom and an internal tube, the internal tube being sealed with respect to a liquid encountering the float support means. A float means is slidably positioned about the internal tube, the float means including a magnet means, the float means being responsive to the level of the liquid. A circuit board means is positioned within the internal tube and includes a plurality of magnetic reed switches. The reed switches are mounted upon the circuit board, the plurality including a first enable switch, second pump switch and a third alarm switch. The pump switch and the alarm switch are physically aligned in a parallel position above the enable switch, the enable switch and the alarm switch each being modified with one shortened lead, thereby modifying the reaction to a magnetic field. the modified reeds eliminate an otherwise conventionally act of state.

Abstract: The linear position transducer of the present invention comprises a pair of elongated electrically conducting members disposed within an elongated tubular container following the length thereof, wherein at least one of the pair of elongated electrically conducting members has a high specific ohmic resistance. A plurality of normally open switches are disposed within the elongated tubular container at regular intervals in a parallel circuit arrangement intermediate the pair of elongated electrically conducting members, which switches are closed by a magnetic force field created by a magnet included in a marker slidably guided by the elongated tubular container.

Abstract: Disclosed is a system for sensing the level of a body of liquid within a container. The system includes a shaft secured parallel to a vertical axis of said container, said shaft having a magnetically responsive digital switch. Further provided is a toroidally-shaped reference element situated circumferentially about the shaft and secured at fixed level thereto, the reference element having a magnetic axis which is co-directional with the axis of the shaft. Also provided is a toroidally-shaped measuring sensing element also situated circumferentially about said shaft and vertically above said reference element but without securement thereto, said sensing element having a magnetic axis co-directional with the axis of said shaft and having a polarity of the magnetic axis which is repulsive in relationship to the magnetic axis of the reference element.

Abstract: To prevent electrochemical corrosion in a conventional float operated variable resistance fuel level detector due to alcohol in the fuel a current pulse is applied to the detector unit once a minute for a period of 1/1000 second. A solid state circuit stores the level reading between pulses and drives the fuel gauge.

Abstract: A sensor and system for measuring the level of a liquid includes a linear potentiometer having a resistance circuit element and a mechanism for changing the resistance of the circuit element including a conductor formed from a semiconducting composition having a resistance inversely proportional to the horizontal force it experiences. The sensor includes an elongated vertical support structure and a float mechanism which is mounted on the support structure to move vertically therealong at the level of the liquid in a fuel storage tank. The float mechanism includes a roller which rolls along the support structure and supplies the horizontal force to the semiconducting composition. The semiconductor composition cooperates with another conductor coupled to the resistance circuit element to produce an electrical signal which is the function of the vertical position of the roller on the support structure.

Abstract: A liquid level electrical alarm apparatus includes a perforated hollow cylindrical sensor housing having upper and lower cup-shaped caps. A cylindrical float contained within the sensor housing contains a permanent magnet near its upper end, effective in closing the contact bars of a reed switch element mounted in the upper cap when the float rises a pre-determined level. The sensor body is suspended by a flexible electrical cable connected to the upper cap. Means are provided for adjusting the length of cable from which the sensor is suspended into a vessel, thereby permitting adjustment of the liquid level which trips the alarm.

Abstract: It will thus be seen that the method for measuring the level of a liquid contained in a reservoir which is subjected to varying accelerations is carried out by means of a level sensor which signals when the level of the liquid drops below a predetermined level, and a warning device which is activated if the sensor signal is applied thereto uninterruptedly for a predetermined minimum period of time and results in maximizing functional reliability of the warning signal issuing means during all types of movement situations of the reservoir, while false alarms are virtually eliminated. This is accomlished in that each occurrence involving the uninterrupted application of a sensor signal for a period which is longer than the predetermined time period (t.sub.1) is registered as an event, and in that the warning device is activated after a predetermined number (n) of events have been registered within a predetermined period of time (m).

Abstract: An on board indicator for vehicles is provided, including a sensor detecting a physical magnitude to be indicated, connected to a display device through a low pass filter whose cut off frequency is increased for a given time after switch on of the vehicle, by appropriate circuitry. A threshold detector controlling an alarm device is connected to the output of the low pass filter. Such an indicator may be used for indicating the fuel level in the reservoir of a motor vehicle, for example.

Abstract: A liquid level indication device including a reed switch activating assembly having a magnet moveable in response to a change in the level of the liquid to effect the closing of the reed switch contact elements when a designated liquid level is reached. The device has a built-in time delay feature to prevent the premature actuation of the reed switch by the magnet should the liquid level in the container only temporarily drop.

Abstract: A device for electrical measurement of the level of a fluid contained in a fuel tank of a motor vehicle is disclosed. In addition to a variable resistance float sensor in a dip tube, a travel sensor is arranged in the dip tube to determine the distance between the dip tube and the bottom of the tank in order to offset measurement errors caused by tolerances in the manufacture of the tank and resultant differences in the mounting position of the dip tube in the tank. The travel sensor includes a spring load rod extending to the bottom of the tank and a variable resistance connected to the rod to produce a calibration value.

Abstract: A low oil cut off switch is provided and consists of a dual magnetic switch within a housing that is adjustably and slideably mounted to transparent tube of a rising stem fuel indicating gauge of a fuel storage tank. The dual magnetic switch which when attached by a magnetic fuel level indicating element within the fuel indicating gauge will first actuate an alarm to indicate a low fuel level in the storage tank and if undetected will next shut off fuel burner operation before the storage tank runs dry.

Abstract: This invention discloses a linear position detector including a pair of elongated electrically conducting members disposed in a parallel arrangement and a plurality of magnetically activated normally open switches disposed at regular intervals following the lengthwise direction of the two elongated electrically conducting members, wherein each of the magnetically activated normally open switches provides electrical connection between the two elongated electrically conducting members when the magnetically activated normally open switch is closed. The combination of the two electrically conducting members and the plurality of the magnetically activated normally open switches are enclosed within a sealed elongated tubular container. A float including at least one magnet is secured to the sealed elongated tubular container in a sliding relationship.

Abstract: An improved liquid-supply reservoir in a liquid-using machine such as a copier is described. The improved reservoir is provided with a pipe and a liquid-level sensing device as one unit, which unit is detachably secured in an opening at the top of the reservoir. A flexible conduit, which has one end associated with the liquid-using machine, can be passed through the reservoir opening such that the other end is close to the base of the reservoir whereby liquid is conducted from the reservoir to the machine or the reverse. Freely slideable floats for sensing a minimum and/or a maximum liquid-level in the reservoir are secured in a recess on the outside of the pipe.

Abstract: A liquid level sensing device utilizing a conductive hollow sphere buoyed by the liquid and guided vertically within a metal tube. An elongated resistance card is mounted in the tube adjacent the sphere to permit the sphere to slide along its surface as the liquid level changes thereby electrically connecting a portion of the resistance card to the metal housing through the conductive sphere. The resistance card is mounted so as to be flexed from its normal flat configuration with the flexed configuration producing a light force on the sphere to maintain good electrical contact therewith and between the sphere and the housing but insufficient to deter the sphere from following liquid level changes.

Abstract: In a liquid level detecting device for fuel or oil in a small size boat, a liquid level detecting switch turned on and off in accordance with a vertical movement of a float provided in a tank and a liquid level warning device are connected in series to a power supply circuit from a generator of an engine.

Abstract: A float assembly for use in tanks, sumps or other liquid-containing vessels includes an elongated, upright, extruded support which maintains individual float switches at preselected heights. The support includes upright, elongated, recess-defining walls with a pair of flat, spaced, parallel sidewall portions that are configured to grippingly engage an outer, deformable insulative covering of a cord connected to the float switch. The cord may be grasped and pulled to an appropriate height, and is thereafter secured by the sidewall portions without the use of tools, fasteners or other components. In preferred forms, the recess-defining walls have a transverse, generally U-shaped configuration with an internal passageway for housing an upper portion of the cord between the float switch and an overlying junction box.

Abstract: Apparatus is provided for controlling the level of steam condensate in a steam retort wherein sealed cans of food are exposed to incoming steam. The apparatus comprises a pneumatically actuated condensate drain valve which is controlled by a solenoid valve and opens to drain condensate if it reaches a dangerously high level, an alarm to indicate when the high level is reached, a recorder to provide a continuous permanent record of condensate level and drain valve status, and an electric control system for sensing condensate level and operating the solenoid valve, the alarm and the recorder in accordance therewith. The electric control system includes a condensate level sensor in the form of a one or more float-operated magnetically-responsive reed switches mounted in the retort. The sensor comprises a hollow stem in which a reed switch is potted in elastomeric non-displaceable material.

Abstract: A hollow float bulb or shell is secured to a flexible electrical cord and encloses a housing which confines an electrical switch and defines a chamber with an inwardly projecting barrier. A weight member in the form of a metal ball is disposed within the chamber and rolls over the barrier to actuate the switch in response to tilting movement of the shell and housing. In one embodiment, a shuttle in the form of a metal frame is supported within the chamber for sliding movement and carries a switch conductor element. The shuttle frame is impacted by the ball located within the frame when the ball rolls over the barrier, and the frame is restrained by magnets to produce snap actuation of the switch.

Abstract: An improved buoyant alarm device which provides an indication of a disturbance to a quiescent level of a body of water. The device includes a cover assembly and a buoyant body. The cover assembly includes a cover member and a support member. The support member provides a subassembly support for electrical components which are mounted thereto and for forming, with the cover member, an enclosed water-tight chamber for housing the electrical components.

Abstract: It is desirable to be able to indicate the quantity of liquid left in the fuel tank of a vehicle. This is conventionally achieved with the aid of a float movable along a resistance wire. The invention offers an improved design of a liquid gauge consisting of two parallel rods (16 and 17),having resistance wires (18,19 respectively) wound around them and being surrounded by a float (6,7,15) with a contact (1-5) connecting the two resistance wires (18 and 19) to each other and arranged between the two wires (18 and 19).

Abstract: This invention pertains to gauge apparatus for measuring liquid levels comprising an elongated electrical sensor adapted to be arranged in upright position while immersed so constructed as to have an electrical resistance which may be varied. A spherical float is magnetically attracted to the sensor for rolling movement with respect thereto for varying the resistance in response to variation in elevation of float caused by changes in the level of the liquid. The resistance is measured thereby to provide an indication of such level. The magnetic attraction holds the float and sensor in operative engagement at all times including those during which the float changes height in response to changes in the level of the liquid being measured. The presence of different liquid is also detected in a given vessel, such as gasoline and water, and an indication and alarm of vessel overfill during a filling operation is provided.

Abstract: A fuel level detector for an automobile fuel tank comprises a strut vertically provided within a fuel tank, a float slidably fitted around the strut and having a permanent magnet therein, a plurality of magnetic induction type reed switches slantedly disposed along the strut with a adequate distance between the adjacent reed switches, the length of which distance being defined such that the permanent magnet of the float always actuates two adjacent reed switches simultaneously, a plurality of resistances respectively connected to the plurality of reed switches for changing current value according to the reed switches which are actuated, a residual quantity warning means having an element of a luminous body which is connected between a ground and a predetermined reed switch among the plurality of reed switches, and a distance retention mechanism for keeping constant a distance between the predetermined reed switch and the bottom surface of the fuel tank and having a guide mounted to a base member for verticall

Abstract: A hydraulic reservoir with fluid level detector includes a main body having an internal space for containing brake oil; a cap attached to the main body for covering a top opening of the main body; a diaphragm arranged across the top opening of the main body, the outer circumference of the diaphragm being held between the main body and the cap, and the space between the cap and the diaphragm communicating with the atmosphere; a reed switch fixed to the main body, a float provided with permanent magnet, so arranged as to be vertically movable in the internal space of the main body, the reed switch and the float with permanent magnet constituting a fluid level detector, and when the float with permanent magnet is positioned under a predetermined level, the reed switch being closed by magnetic force of the permanent magnet; an operating rod for pushing down the float, being vertically movable and able to be pushed down from the external against buoyancy of the float; and a cylindrical portion integrally formed wi

Abstract: A liquid level control apparatus which detects a liquid level in a tank employed, for example, in ice making equipment, to thereby trigger a control operation. The level control apparatus comprises a tank containing a body of liquid, a float movable in response to the vertical movement of the surface of liquid within the tank, a hollow case having a closed top and an open bottom, and a guide member disposed within the case for guiding the vertical movement of the float. The hollow case is arranged so that the open bottom thereof is closed by the rising liquid to thereby from a hermetically closed chamber within the case. An upstanding tubular member extends into the hollow case such that the lower end of the tube defines a level of liquid at which the hermetically closed chamber is formed. The chamber thus formed is effective for preventing the guide member from being immersed in the liquid to assure smooth movement of the float.

Abstract: A water flow failure detection device comprising a first water flow conduit; a second conduit with one end closed and the other end open communicating with the water flow conduit; positioned within the second conduit is a float which is free to translate therein. The float includes a permanent magnet positioned around its longitudinal mid-section; and a reed switch located on the external surface of the second conduit whereby the flow of water through the first conduit sufficiently raises or elevates the float away from the reed switch allowing the reed switch to return to its normal state and an absence of water flow causes the float to translate downward due to gravity to a location adjacent the reed switch thereby changing the state of the reed switch. The reed switch change of state can be used to terminate fuel or ignition to an engine or operates an alarm signal in the absence of cooling water flow through the engine.

Abstract: A fluid level sensor comprising a pivoted float which contains a solid-state inclinometer that produces sensitive electrical output signal responsive to angular displacement of the float from the direction of gravity. The float is capable of resolving very small changes in liquid level in a vessel, and thereby indicating or warning of small leaks from the vessel. A reference inclinometer may also be provided for producing a reference signal to compensate for fluid level signal errors caused by motion of the vessel.