Abstract: An apparatus for detection of the level of a liquid metal is disclosed. The apparatus has a liquid level detecting probe provided with an exciting coil wound in a closed bottom non-magnetic sheath over the approximately whole length thereof, a level detecting coil wound in the sheath in an upper part thereof, and a temperature compensating coil wound in the sheath in a lower part thereof; a temperature control for maintaining the coils at a constant temperature; a drive circuit for supplying the exciting coil with an alternating current of a determined frequency and amplitude; and a signal processing circuit for subjecting output voltages induced in the liquid level detecting coil and in the temperature compensating coil to linear detection and then determining the ratio of the thus detected outputs, thereby detecting the level of the liquid metal.

Abstract: A liquid level detecting apparatus for detecting the level of a conductive liquid, comprises a pair of electrodes which are either connected with or disconnected from each other depending on the liquid level, an oscillation circuit which is variable in the state of its oscillation signal in response to the variation in impedance between the pair of electrodes and applies between the pair of electrodes an AC signal in synchronism with the oscillation signal, and a switching circuit which detects the liquid level in response to the oscillation signal, whereby dissolution of ions from the electrode into the liquid is prevented.

Abstract: An alloy composition comprises lead, tin and zinc, each being present in an amount of between about 20 and about 45% by weight. Preferably, the composition also contains small amounts of up to about 0.1% each of copper and tellurium. When in contact with water or other aqueous composition, the alloy generates a current directly proportional to the alloy surface area exposed to the liquid.

Abstract: A digital readout fuel gauge for monitoring the liquid level in a fuel storage tank. The device utilizes a pre-amplifier circuit which comprises a voltage divider network utilizing the fuel gauge tank variable resistor on one side of the divider and a variable resistance on the other side which is connected to a signal processor. The output voltage of the signal processor is connected to the analog input of an analog to digital converter. The analog to digital converter changes the DC voltage levels to a four bit BCD code. The output carrying the code is connected to a decimal digit to a seven segment LED decoder. The digits are generated and displayed on LED indicator units. In addition, a voltage comparator circuit compares the output of the signal processor with a reference voltage and when said output is below a predetermined level, the comparator circuit initiates a warning signal.

Abstract: A device for the automatic determination and recordation of rates of fluid absorption in soils, including a plurality of conductive probes which are positioned at various levels with regard to a provided water level such that as the water level drops, the time to accomplish the drop is recorded. The device provides a pair of timing and time recording devices interconnected with the probes such that two individual time sequences may be recorded.

Abstract: Method and arrangement for measuring and controlling the level of a fluid in a container. The conductivity of the fluid is measured by means of a detector and a high-frequency voltage supply. The detector operates on a capacitive or on an inductive basis. Means for eliminating the effect of the size of the container and of the transfer functions of the detector and, in the control arrangement, the pump.

Abstract: A plurality of horizontally and vertically spaced apart remote liquid level sensor assemblies free of upwardly directed surfaces operatively connect only under emergency conditions to the sump tank of a sewerage system through vertical housings connected to horizontally extending drain lines connected to a sump tank and reliably indicate such emergency conditions for timely corrective action and avoid flood damage.

Abstract: A froth level monitor is disclosed. The froth level monitor comprises a plurality of electrically conductive electrodes spaced in the vertical direction and adapted to contact the top of the froth in sequence as the level of the froth rises, a constant current source connected to each electrode and capable of generating a constant current when its associated electrode is in contact with the froth, and a summing and time averaging current to voltage converter connected to the output of all the constant current sources for summing up all the currents as an indication of the number of electrodes in contact with the froth and for averaging with respect to time the variations in froth level so as to provide an indication of the mean level of the froth.

Abstract: A probe for detecting the level of electrically conductive liquids in a walled container having an inner chamber consisting of a probe housing having a bottom portion for insertion into the chamber of the walled container, and an inner chamber, an insulated packing secured in the housing on the bottom portion, at least one compensating electrode having an insulating jacket and disposed through the packing, the insulating jacket penetrating the packing and extending into the container and at least one measuring electrode having an insulating jacket and disposed through the packing, wherein the electrode is elongated and spaced apart from the compensating electrode and extends beyond its insulating jacket into the container.

Abstract: A device for monitoring the amount or depth of silage or similar material retained in a silo or like structure is disclosed. A number of sensors are vertically arrayed in and on a silo wall, and each sensor senses the presence or absence of silage in its immediate vicinity. An electrical circuit includes a visual display device such as a liquid crystal display for indicating the amount of material in the silo.

Abstract: This specification discloses a molten steel level determining device in which the electrode senses the interface between the molten steel and the slag on the molten steel at a predetermined level within the deeming ladle whereby the amount of steel remaining in the ladle may be more accurately determined than by prior art methods. With the aid of this information, the standard pourdown practice is modified to ensure that unrollable ingot butts are not poured. The level indicator may also be used to determine the level of other liquids in environments where known methods are not practicable.

Abstract: An electrode device for use in monitoring conductive liquids consisting of a mounting with a first electrode having a tie rod portion disposed through the central opening of the mounting and a clamping collar secured to the tie rod adjacent to one side of the mounting. The first electrode then extends further in an extending portion and is surrounded coaxially by a second tubular electrode which is connected through a contact sleeve disposed in the central opening of the mounting. There is also a counterelectrode coaxially surrounding the second electrode and secured to the mounting surface. The second electrode has an end flange portion with a passageway for receiving the rod portion of the first electrode. The clamping nut secures the rod portion of the first electrode and the end flange between insulating washers to the mounting.

Abstract: A resistive fluid detecting means utilizes a probe means having three electrically conductive areas that are interconnected between a power source and an amplifier. The detecting means is particularly useful in detecting the presence or absence of water in a boiler used in a heating plant. The presence of water between two of the electrically conductive areas reduces the resistance of that path so that the amplifier responds and operates an output switch, which in turn can be used to energize a fuel burner for the boiler. If boiler scale builds up on the probe means or if the water or fluid rises too high, the electrically conductive areas shunt current away from the amplifier and allow the output switch to open.

Abstract: A liquid level control system is disclosed. The system includes at least one level sensing electrode which is fixedly mounted to a vessel and projects therein. The probe is adapted to contact a fluid within the vessel to utilize the electrical conductivity of the fluid to complete a circuit when the fluid contacts the probe. The probe is coupled between a point of reference potential and the control electrode of a single silicon controlled rectifier (SCR). The main electrodes of the SCR are serially coupled with the coil of a low-voltage A.C. relay and the secondary winding of a step-down transformer. Accordingly, the use of a relatively low secondary voltage avoids shock hazards; and, the sensitivity of the system is increased by the effective gain provided by the SCR. The use of an A.C. current in the probe avoids the galvanic corrosion which otherwise follows from D.C. current operation.

Abstract: An electric storage battery is disclosed having a case to retain electrolyte up to a given preferred level, cover means for retaining the electrolyte within the case, said cover means having defined therein at least one bore, said bore comprising at least one constricted section, probe means for sensing the preferred level of the electrolyte, said probe means being disposed through the cover, and resin means for chemically sealing at least a portion of said probe means with said cover means. In addition to the above, the present application discloses an inter-relationship between the remainder of the probe and the bore which allows for the introduction of resin between the surfaces of the probe and bore to create an effective seal between the probe and battery cover. Finally, a unique configuration of probe and bore is disclosed which produces a strong electrolyte tight seal between the probe and battery cover.

Abstract: A liquid metal level sensor of the bifilar wound coil sensor type in which the secondary windings are of a lesser diameter than the primary windings for unbalanced operation.

Abstract: A method and apparatus for measuring the level and dielectric constant of a liquid which includes a device for generating a subnanosecond baseband pulse that propagates through a transition device to a single wire transmission line that extends through an air filled region into the liquid. A discontinuity created at the air liquid interface produces a reflection of the baseband pulse that is compared with the transmitted pulse with respect to time of arrival and amplitude to determine the liquid level and the reflection coefficient at the air liquid interface. The reflection coefficient is then utilized to determine the dielectric constant of the liquid.

Abstract: A probe for use in a fluid level sensing system has an electrode and an insulating body located between the ends of the electrode. The insulating body is in the form of a hollow, tubular shell and includes electrode carrying parts ad resilient fluid container wall engaging parts. The electrode and container wall engaging parts are spaced along the longitudinal axis of the electrode so that, when the probe is mounted in its operative position in an opening in a fluid container, the container wall engaging parts resiliently engage the container wall parts which bound the opening, and the electrode is supported by the shell at a position within the container and spaced from the container wall.

Abstract: A device for indicating the presence or absence of liquid at a single level in a tank, comprising a sealed cylindrical housing having one end wall permanently fixed and the other end wall removable. The housing has an internal shoulder against which the removable wall is seated. The latter has an annular recess extending about its periphery in which there is disposed an O-ring, adapted to sealingly engage the housing wall adjacent the shoulder and thus effect a watertight seal therewith. The removable wall is connected to the fixed end wall by means of draft screws and sealing nuts, the screws having spacers which mount two printed circuit boards in spaced relation with one another inside the housing. The removable end wall also carries at its outer side two concentric, conductor tubes on feed-through insulators, constituting a probe whose conductive or capacitive characteristics vary according to whether the tubes are submerged or dry.

Abstract: A probe of the mutual inductance type with a linear response which is independent of temperature comprises a rigid support, two insulated cables disposed in interengaged relation and wound on the support, means for supplying one of the cables C.sub.1 with alternating current having constant amplitude and frequency, means for measuring the voltage between the two extremities of the second cable C.sub.2. A single resistor R is placed between the extremities of the cable C.sub.2, the resistance value of the resistor and the value of the frequency f being determined so as to ensure that the variations in voltage measured between the extremities of the cable C.sub.2 are reduced to zero in respect of any given level of liquid outside the probe.

Abstract: A digital transducer comprises a container having two disparate materials therein defining an interface, the interface being movable through the container responsive to a force, or forces, applied to one, or both, of the materials. A plurality of sensors are spaced along the container for sensing the interface, each of which is responsive to the presence of one of the materials. Means are included for suppressing the outputs of all of the sensing means responsive to the one material except that one sensing means which is responsive to the one material and nearest the interface.

Abstract: A liquid level shutoff control for minimum level control of conductive fluids. A pair of electrodes are disposed in the liquid at the minimum level desired for the fluid. The electrodes provide a conductive path for a high frequency electrical signal and circuits energize a controlled load such as a liquid heating or mixing apparatus whenever the electrodes are in contact with the fluid. Failure of the control circuit results in shut off of the controlled load thereby providing fail-safe minimum level control.

Abstract: In a preferred embodiment of the invention, there is provided a laminated vessel wall which is able to enclose electrically conductive liquid with a know electrical property and which vessel laminated wall has alternate electric conductive and non-conductive layers of horizontally-lying whole-circumscribing frame elements lying one stacked on the other, the non-conductive layers being transparent for easier observation of the position of the liquid, and the position of the liquid within the enclosed vessel wall can be determined outside of the vessel wall by using the electrical conductivity of the electric-conductive layer which establishes a closed electrical circuit through the liquid and the vessel wall by directing conducted through a convenient outer measuring mechanism having a sliding contact contactable separate with each of the conductive layers, and this measurement of the position of the liquid being accomplished by the establishment of electrical circuit through the liquid, a conductive layer of

Abstract: The invention disclosed in the specification is directed towards an impro device for measuring liquid levels and specifically provides a pair of capacitance probes, one of which is coated with a dielectric material, positioned in a stilling well which is coupled to a conical housing for an entrance orifice to provide controlled level changes; and, in addition is provided with electronic circuitry and recording equipment and power pack.