Abstract: An apparatus for indicating by electromagnetic means the level in metallurgical vessels means with transmitting and receiving coils which combined into a measuring unit having a transmitting coil which extends in the direction of the fill height and at least two receiving coils assigned thereto and staggered vertically. This simplifies and facilitates the assembly work.

Abstract: A burden distribution monitoring apparatus, according to the present invention, includes a hollow cylindrical sonde having an inner end radially movable within the internal space of a furnace, such as a shaft furnace. The sonde carries a burden layer depth sensor and/or a burden grain distribution sensor for radially shifting working ends of the sensors. With the foregoing construction, burden depth and/or grading of the burden can be monitored in a plurality of radial points in the furnace.

Abstract: A device for indicating a physical quantity such as depth in water by means of a pointer moving around a numbered face, using a C-MOS type computer for sampling the physical quantity at regular intervals and calculating the increment between the preceding value and the last value of the physical quantity. A pulse motor drives the pointer as many steps as are required for reaching the position at which the pointer indicates the last value of the physical quantity. The use of a sampling system and a pulse motor renders the device small enough so that it can be incorporated in a wrist watch.

Abstract: A capacitance fuel-gauging probe is supported at its upper end in a fuel tank by a stress-relieving mount. The mount includes a disc assembly formed of two identical steel discs each with a central aperture. The discs are joined together at their respective outer edges and around their respective central apertures by steel rings which separate the discs from one another, forming an annular recess. The ratio of the estimated disc stress to the disc material proof stress, and the ratio of the estimated probe stress to the probe material proof stress are substantially the same and as small as possible. A bolt extends through the aperture, the probe being clamped to the center of the disc assembly by a nut. The outer edge of the disc assembly is clamped securely with the wall of the fuel tank by a collar screwed into a sleeve within which the disc assembly is located. Any vibration of the probe during use causes flexing of the disc assembly so as to damp the vibration.

Abstract: High amplitude signals reflected back to the horn radiator-receptor in a microwave tank-contents measuring assembly from the interface between a microwave dielectric lens and the tank-contents-atmosphere, which reflected signals mimic returning ranging signals and interfere with detection of returning legitimate ranging signals, are substantially canceled by incorporating in the lens which is plano-convex a thin layer of electrically conductive material in a plane parallel to the plano surface of the lens, said layer being formed from a uniform array of a repetitive pattern of regions containing the conductive material alternating with regions free of said material. One embodiment has an hexagonal array of circular conductive regions while another embodiment has the conductive material in the form of a rectilinear grid.

Abstract: A method and device for measuring the distance to an object, particularly the distance to the surface (17) of a liquid in a container (15). An antenna (11) is arranged a distance from and aimed against the surface, the antenna being connected to a measuring unit (12), a channel unit (13) and a control unit (14). A microwave signal with a predetermined frequency is generated in the measuring unit (12), of which a part is utilized as a reference signal, while a further part is input to the antenna (11) and transmitted against the surface (17). From the reflected signal received by the antenna and supplied to the measuring unit (12) and the reference signal, a function of the antenna input reflection coefficient is determined. This function is adapted to the current condition. A fourier transformation of a set of values of this function at a certain set of measuring frequencies is made, from which the distance to the surface is calculated.

Abstract: A level gauge for liquid helium comprising a sensing element in the form of a ribbon wire made of superconductive alloys and a tube supporting the sensing element, which tube is inserted into liquid helium upon measurement. The superconductive alloys are represented by a formula Zr.sub.100-x.(Ru.sub.y.Rh.sub.1-y).sub.x in which x represents contents of Ru and/or Rh in atomic % and in a numerical value of 22.5.ltoreq.x.ltoreq.27.5 and y represents a numerical value of 0.ltoreq.y.ltoreq.1. The alloys are made of an amorphous phase obtained by rapid quenching a molten alloy material and have a superconducting transition temperature, Tc, of 4.2.degree. to 4.5.degree. K. When the level gauge is immersed in liquid helium, a portion of the sensing element below the level of the liquid helium has a zero electric resistance because of the superconductivity of the alloy, so that the level of the liquid helium can be detected by a variation in resistance of the sensing element.

Abstract: A method for remotely measuring the level of a bulk material in a vessel, wherein the bulk material comprises loose particles, with adjoining particles defining interstices therebetween. Liquid is added to the vessel at a constant flow rate through a liquid inlet of the vessel, wherein the liquid progressively fills the interstices of the bulk material from the bottom of the vessel to the surface level of the bulk material. The liquid level indications of a level measuring device are monitored as a function of time. The level at which the rate of change of liquid level in the vessel decreases is determined. Such level represents the surface level of bulk material in the vessel.

Abstract: A liquid level indicator for use in monitoring the level of fluid in a reservoir remote from the user is disclosed. The indicator includes a receiving tube adapted to receive a quantity of fluid having an elevation reflective of the oil in the reservoir. The fluid is then confined by a reciprocating closure tube. A piston member is then depressed into the confined oil pressurizing that oil until an equilibrium position is obtained. The piston head is held in a constant spaced relationship with an indication element which is remote from the fluid reservoir. The amount of displacement of the piston head within the receiving tube is reflected by reference indicia carried by the indication element to indicate the level of fluid within the reservoir.

Abstract: An apparatus for measuring the level of molten metal in the oscillating mold of a continuous casting machine in operation by an eddy-current type distance measuring device. The oscillation signal component due to the oscillation of the mold is extracted from the output signal of the distance measuring device and the detection sensitivity of the distance measuring device is compensated and controlled so as to maintain the amplitude value of the oscillation signal component at a constant value thereby linearizing the molten metal surface level versus output characteristic.

Abstract: A liquid level indicator system is provided for sensing the presence of liquid at a preselected level in a liquid containing container. A piezoelectric reed transducer is disposed in the container for detecting vibrational movement and for producing an electrical signal in response to the vibrational movement. Operationally coupled to the transducer is a paddle which is sized to be immersed in the liquid when the liquid is present at the proper level. Immersion of the paddle in the liquid inhibits the transducer from vibrating due to fluid resistance against the paddle and accordingly inhibits an electrical signal output from the transducer. A control circuit is provided for sensing the electrical signal generation and for generating an alarm signal representative of low liquid level. A tubular housing is provided for containing a level of liquid representative of liquid level in the liquid container. The reed is preferably tuned to a preselected natural frequency sympathetic to ambient system vibrations.

Abstract: A device for measuring the oil level in an internal combustion engine, which enables an oil dipstick to remain in the oil filling opening to engines even during filling. At its upper end the dipstick is connected to a cap for the oil filling opening, and the dipstick is intended to be accommodated in a tube or a like device communicating with an oil container for the engine. The invention is substantially distinguished in that the dipstick is articulately connected to the cap and allows tilting of the dipstick relative the cap, enabling the cap to be hung on the upper edge of the tube during oil filling.

Abstract: In a method of measuring the level of a flowing material kept in a container there is employed a microwave signal that is fed from a transmitter through a tubular waveguide (7) that extends vertically downwardly through the container and communicates therewith so that the surface (10) of the material in the waveguide follows the level of the surrounding material. The signal is reflected from the surface back up through the waveguide and is conducted to a receiver to be employed, after signal processing in an electronic unit, for determining the level of material in the container. The microwave signal is fed to the waveguide by way of a mode generator (11) that produces only one dominant propagation mode of the signal, the wavelength of which is smaller than the diameter of the waveguide (7).

Abstract: A device for detecting sealing defects and for measuring the leakage rate of gaskets placed in parallel relationship on the lateral surface of a gate separating the compartments of a storage pool for nuclear fuel elements has a small volume of free space between the gaskets. This volume is connected by means of a tube with two leakage level detectors placed at different levels which emit a signal when a predetermined water level is attained in the tight volume.

Abstract: A local display of a fluid level is provided in connection with a fiber optic illuminating system in which a side by side, bi-color light is passed through the fluid in a level gauge having transparent viewing ports. Diverging light passing from the level gauge, refracted in response to the fluid and gauge material, is masked and one color is passed to a focusing lens and a local readout in a plane above or below the focusing lens.

Abstract: The present invention relates to a liquid level meter, comprising a coil having a core, a float which is provided at the external circumference of coil so that it can move in the longitudinal direction along the same core and comprises a conductor ring, a detector which detects change of inductance of coil in accordance with movement of said float namely conductor ring, a converting circuit which converts change of inductance detected by the detector into change of voltage and a liquid level indicator which is driven by a drive circuit in accordance with such conversion.

Abstract: A moisture intrusion detection system is provided, wherein a plurality of independent and insular moisture detecting units are placed in a predetermined spaced apart relationship across the surface of a roof structure, or other system incorporating a water impermeable membrane, beneath the water impermeable membrane thereof. Each of the detecting units includes a moisture detecting and power supply unit and signalling unit. When moisture penetrates the water impermeable membrane of the roof structure, a leak condition exists and a water activated battery is activated. Each detecting unit in contact with water is activated. In combination with the detecting units, position and direction locator apparatus are used in combination with the detecting units to localize the source of the leak and the extent of any water damage caused thereby.

Abstract: A liquid level measurement capacitance probe is disclosed comprising an elongated outer capacitor tube, an elongated inner tube coaxially mounted within the outer capacitor tube to form a capacitor annulus therebetween with the inner tube having a plurality of longitudinally extending capacitor elements cooperating with the outer capacitor tube to form a plurality of individual capacitor units, a connector unit for electrically connecting the capacitor units to an electronic circuit processor for measuring capacitance values of the capacitor units in calculating a fluid level, a filter for separating water from fuel flowing from the storage tank to be measured to the capacitor annulus, the filter having an annular housing mounted about the outer capacitor tube with an inlet port adapted for fluid communication with the storage tank, an outlet port connected to the capacitor annulus between the inner and outer capacitor tube for delivery of filtered fuel to the annulus, a water discharge outlet for discharging

Abstract: A filling level measuring probe detects the filling level in a container by suppression of an oscillator by contact with a filling material. The oscillator consists of a hollow body 16, which can be connected through a shaft 14 and a screw-in part 12 with a container wall 10 and is set in oscillation with oscillations in the radial direction over a crosspiece 20 mounted in hollow body 16 by means of an electromechanical transducer 26 which is mounted on crosspiece 20. The oscillations are converted by a second electromechanical transducer 28 into an electric signal, of which the amplitude is changed with suppression of the oscillations as a result of contact of the hollow body 16 with the filling material.

Abstract: A liquid coolant measuring instrument for a nuclear reactor vessel measures the liquid coolant level by utilizing the thermal characteristics of the medium surrounding the instrument. The instrument has an elongated cylindrical body having a number of difference thermocouples disposed within at various levels. A sectional electrical resistance heating element is located within the elongated body. The heating element heats one junction of each difference thermocouple and by monitoring the increase in temperature signal at different levels within the vessel, the liquid level can be determined. The instrument is also provided with a shield tube that surrounds the instrument forming an annular space therebetween. Liquid coolant enters the tube through a bore having a baffle that strips entering liquid of entrained non-liquid bubbles such as steam and gasses, thereby providing measurement for the actual liquid coolant level and not the expanded coolant level.

Abstract: Disclosed is a monitoring system and method for detecting the presence or absence of material at a location. The apparatus may generally be constructed to include a sensing unit, including an antenna probe for positioning at the location wherein material is to be detected, and a control unit for responding to signals from the sensing unit indicating the presence of material at the antenna probe. The control unit may include an indicator to inform an operator of the presence or absence of material at the antenna probe, and also an output which enables peripheral equipment to operate only under selected conditions at the antenna probe. The sensing signal from the sensing unit is dc, with fluctuations indicating the presence of material at the antenna probe.

Abstract: An oil level sensor assembly adapted for installation in an automobile engine crankcase at the level corresponding to "low oil". The sensor assembly utilizes the principle that air is expandable whereas oil is not. Accordingly, when it is desired to sense the oil level, a predetermined amount of fluid is trapped within a chamber sealed by a diaphragm. If the oil level is adequate, then the sensor will be below the oil level and the trapped fluid will be oil. However, if the oil level is low, the trapped fluid will be air. After the fluid is trapped, a spring operating on the diaphragm attempts to expand the chamber. If the admitted fluid is air, the chamber can be expanded and a switch contact will be made, to provide an indication of low oil level. On the other hand, if the chamber is filled with oil, the chamber will not expand and the switch contact will not be made.

Abstract: A method for detecting the surface level of a molten metal, particularly in a continuous casting process, utilizes the thermal radiations emanating from the surface of the metal. An antenna is directed so that its beam width encompasses a portion of the surface of the metal and the adjacent inner wall of the mold or container. The interference between radiations that propagate directly to the antenna from the surface of the metal and those that are reflected off the container wall is measured in terms of its electric power, i.e., the electromagnetic component of the radiations. Fluctuations in the measured electric power are indicative of changes in the level of the metal.

Abstract: The present invention relates to a device making it possible to detect variations in the height of the free level of a liquid in an enclosure.The device comprises a vertical short tube issuing into the upper part of the vessel and whose upper end issues into a first condensation pot, a long tube whose long end issues into the vessel at a level below that at the end of the short tube, the end of the long tube being provided with a hydraulic seal, while the upper end of the long tube issues into a second condensation pot, a differential manometer indicating any pressure differences between the two condensation pots.Application to the measurement of the level of the water contained in the vessel of a pressurized water nuclear reactor.

Abstract: A microwave tank-contents level measuring system is housed within a housing having an open end obturated by a hyperbolically curved convex-plano fluid impermeable solid dielectric lens providing a seal for the tank opening over which the housing is installed while collimating the outgoing ranging signal and focusing the return signal. A separate removable housing cover provides access to the electronic components for service while the tank-opening sealing function of the lens is not disturbed. A transmitting-receiving horn is dimensioned and positioned on the axis of the lens with its effective phase center at the operating frequency coinciding with a focal point of the hyperbolic surface.

Abstract: A tool for use in sampling bottom sediment conditions in oil storage tanks utilizing a thief suspended on a rope. The bottom sediment sample is taken through a thief hatch opening in a tank top adjacent the tank peripheral edge. The tool is an elongated slender member having a U-shaped outer end for receiving the rope, the tool being dimensioned for extension through the tank thief hatch and having an inner end engageable by the user so as to retain the body member generally horizontally within the tank and leave the gauger's hands free so that the thief may be lowered into the tank in areas displaced away from those areas vertically below the thief hatch.

Abstract: A cage-like protector lowerable down a fill tube of an underground tank to protect the bottom wall thereof from damage by a dropped dipstick.

Abstract: A fuel gaging system of the type wherein the capacitance of a probe (20) within the fuel tank is used as an indication of fuel quantity via an assumed density/dielectric constant relationship (10) of the fuel. System accuracy is improved by directly measuring fuel density and dielectric constant. These values are compared with the assumed values in a processor (68) which generates an appropriate gaging correction signal in response to a discrepancy.

Abstract: A level detecting device for detecting the level of liquid in a tank includes a displacer or float displaceable in response to the level of the liquid in the tank, an enclosure tube disposed on the tank and sealed thereagainst so that the exterior of the enclosure tube is isolated from the liquid in the tank and a variable transformer for detecting the displacement of the float. The transformer includes at least two windings disposed adjacent the outside of the enclosure tube and an elongate core disposed within the enclosure tube and coupled to the float so as to be movable therewith, the amount of magnetic coupling between the windings being dependent upon the position of the core in the enclosure tube. Means are provided for generating an output signal representing the amount of magnetic coupling between the windings to derive an indication of the level of the liquid in the tank.

Abstract: A fuel gauge includes a stationary capacitor located within a fuel tank in such a manner as to be partially immersed in the fuel so that the capacitance of the capacitor varies with the level of fuel. A measuring device determines the capacitance of the capacitor to measure the level of the fuel or the amount of fuel remaining within the tank.

Abstract: A method and device for measuring the fluid level in a container. A column f fluid within the container is momentarily subjected to pressure, which causes the column of fluid to vibrate. The oscillation frequency is then measured. Since the frequency depends on the fluid level, the fluid level may be determined from the frequency of oscillation.

Abstract: The level of such granular materials as fly ash and grain in a hopper presenting a differential internal hopper pressure above and below the level of materials in the hopper is sensed by sampling the pressure through a single flowless pressure conveying passageway extending by means of a port into the hopper interior. The pressure significantly changes above and below the level of materials. Thus, typically with a vacuum of about eight inches of water above the material level, the vacuum pressure is less than one-half an inch of water when the granular materials cover the port. Thus, a differential pressure gage connected between the atmosphere and the flowless pressure conveying passageway will indicate a significant difference in pressure when the level of materials covers the port. With a pressure gage operating relay contact an electric monitoring and control system may be used to automatically discharge the materials over long periods of time without maintenance.

Abstract: A fluid amplifier for sensing the level of a liquid in a reservoir, storage tank or other container and for generating a differential in pressure signal in response to the static presence of the liquid level at a predetermined level. An inlet develops a liquid flow stream. A first passage of major cross-sectional dimensions is provided for delivering a major portion of the flow stream to the reservoir or storage tank. A second passage of minor cross-sectional dimensions is spaced laterally of the first passage for developing a small signal fluid power stream substantially parallel to the major supply stream. A sensor is responsive to the static presence of the liquid level at the predetermined level for altering the smaller fluid power stream from its substantially parallel flow condition to a condition in which it diverts and attaches to the major supply stream.

Abstract: A precision liquid level sensor utilizes a balanced R. F. bridge, each arm including an air dielectric line. Changes in liquid level along one air dielectric line imbalance the bridge and create a voltage which is directly measurable across the bridge.

Abstract: An apparatus and method for measuring the height of a liquid above a reference level in which short pulses of subnanosecond duration are coupled to a dual-mode transmission line immersed in a liquid to propagate thereon in a plurality of modes. A surface wave propagating on the outer conductor is reflected from the surface of the liquid, and coaxial-mode propagating within the transmission line is reflected from the reference level. These reflected pulses propagate back along the transmission line, coupled to a receiver for detection, the detected pulses processed to determine the liquid height above a reference level.

Abstract: Apparatus for measuring the total mass of the fluid in a container, having pressure responsive, density determination means adapted to determine the localized density of the fluid as a function of pressure differential between two closely spaced, vertically separated measuring points in the fluid, means enabling the density determination means to determine the localized density values throughout the depth of the fluid, storage means for storing predetermined horizontal cross-sectional area values of the container as a function of depth, and computational circuitry responsive to the density determination means and the storage means for providing a total mass signal corresponding to the integral, over the depth of the fluid, of the product of localized density values times the corresponding area values.

Abstract: A device capable of measuring the position of the level surface of a molten metal bath by exploiting a microwave signal emerging from a waveguide which impinges perpendicularly onto the molten metal so as to originate a standing wave, the position of which is determined by the position of the level surface. The parameters of the standing wave are detected so as to obtain an indication as to the level.

Abstract: A liquid gaging system comprising a plurality of sensors, each sensor providing a liquid measurement signal relating to a liquid depth at a particular location in a tank. The invention also comprises apparatus for selectively monitoring individual sensors one at a time. The apparatus for selectively monitoring is connected to the sensors.

Abstract: Apparatus for indicating quantity of liquified gas contained in a storage container for supplying gas to a consuming appliance, the apparatus including a pressure sensor for sensing gas pressure within the container and being arranged to operate an indicator which gives a desired indication, the indicator being calibrated to indicate the quantity by weight or volume of liquified gas contained in the container.

Abstract: Swimming pool water level control apparatus includes a remote indicator for sensing the water level in a swimming pool and for turning on and off a water flow control valve to provide water for the swimming pool.

Abstract: Improved and simplified measurement of the level of molten metal in a crucible heated by an induction coil utilizes a variable frequency power supply for the induction coil. Power supply frequency is changed to maintain the power provided to the coil substantially constant, independent of variations of power factor in the coil circuit. Detection of the frequency of power supplied to the induction coil provides an indication of the changes in power factor of the coil due to changes in the level of molten metal surrounded by the coil, and thus of the level of the molten metal.

Abstract: Apparatus for breaking up stacks of boards in a power saw has a platform which carries a stack of boards and is movable upwardly by a motor which is automatically arrested in response to lifting of a preselected number of boards above a given level. The unit which effects the transfer of boards above such level onto a table which supports the boards during cutting carries a pivotable lever with an idler roller which rests on the topmost board during lifting of the platform, and the lever causes a switch or a signal comparing stage to arrest the motor for the platform when it assumes a preselected angular position. When the idler roller is moved off the topmost panel in response to transfer of the selected number of boards onto the table and resulting movement of the transfer unit relative to the platform, the lever assumes a given position in which it arrests the motor for the transfer unit.

Abstract: To measure the height of the surface of a fluent material, such as coal, in a bunker or container, pulsed radiation from a microwave source is beamed down on to said surface, and the return radiation reflected from the surface is processed to detect pulses in the waveform with time-varying amplitudes, and therefore denoting returns from the fluent material, and to reject fixed shape pulses denoting returns from the fixed structure of the bunker. To discriminate between returns of time-varying amplitude (i) from the fluent material surface and (ii) from material flowing in from an in-feed, the higher frequency components, denoting the material flowing in, are filtered out.

Abstract: A method and apparatus are provided for monitoring the length of a liquid column such as the filling level of a beverage bottle. A predetermined high frequency signal is applied to a parallel circuit wherein, in one branch, a liquid column is connected by means of electrodes coupled to the ends of the column such that the column, i.e., a filled bottle, will produce more or less resonance in the first branch. The increase or decrease of resistance at resonance in the first branch will be reflected in a corresponding change in the power or current detected in the second branch. In instances where preset limit values are exceeded, an error is indicated and the improperly filled bottle is removed. When monitoring the filling level of beverage bottles, the latter are successively guided past the electrodes, with the upper electrode being coupled to the necks of the bottles through an air gap.

Abstract: An apparatus for measuring the liquid level adjacent the bottom of a slurry vessel is provided with a liquid level indicator that works in conjunction with a flow conduit which passes through a container with an imperforate side surface that covers a first open-topped fluid retaining container to permit the liquid within the slurry vessel to enter the open-top first fluid retaining container and the flow conduit in response to the level of liquid within the slurry vessel.

Abstract: Apparatus and method for detecting the presents of an interface between two fluids with a conventional interface detection apparatus, located remote from the interface, in a tube are disclosed. The apparatus and method utilize a driving fluid introduced into the tube to cause one or the other of the fluids forming the interface to flow from an end of the tube through the tube to the remote detection apparatus, permitting the latter to test the fluid in the tube to determine whether the interface is above or below the end of the tube.

Abstract: A shield is disclosed which protects the bottom of liquid filled tanks in general and underground flammable liquid storage tanks in particular. The shield is slidably secured near the bottom of the fill drop tube which is positioned within the tank. The shield bottomly covers the drop tube in a manner to protect the tank construction during stick gauging. When a gauge stick is dropped into the tank through the fill opening to measure the quantity of liquid contained therewithin, the gauge stick strikes the shield and not the bottom of the tank.

Abstract: A powder level measurement probe is described for use in a polypropylene gas phase reactor. The apparatus comprises a support tube which extends downwardly from the upper end of the reactor and which has a non-metallic powder probe holder mounted on the lower end thereof. The holder is provided with upper and lower recessed areas formed therein. A metal proximity sensor is positioned in the upper recessed area and is operatively connected to a signal device such as a light or the like which is positioned remote from the reactor. A metal plate is movably positioned in the lower recessed area of the holder and has a probe secured thereto which extends downwardly therefrom which is adapted to be engaged by the powder within the reactor. Movement of the probe by the powder causes the metal proximity sensor to be activated which in turn activates the signal device connected thereto.

Abstract: A method and apparatus for measuring the amount of mire and mud in a suction dredge hopper 2, which mire and mud is a constituent of a fluidized mixture. An acoustic level gauge 16 measured the position of the upper surface 3 of the mixture and a plumb weight 7 measures the position of the lower limit of the mixture defined by the top of a sand layer 4. A plurality of differential pressure responsive density measuring devices P measure the density of mire at different levels. From these measured valves the total amount of mud and mire is determined.

Abstract: An apparatus and method for using microwaves to measure the level of liquid within a container comprising a waveguide for immersion into the liquid, an oscillating means for propagating a sweeping frequency electromagnetic signal down the waveguide for reflection from the surface of the liquid, impedance matched means for receiving the reflected signal and means for comparing the frequency of the reflected signal to the frequency of another output signal of the oscillating means, whereby the frequency difference corresponds to the time of travel of the signal within the waveguide and therefore the distance the signal travels before reflection.