Bindicator Company

Other

Berwind Corporation

Venture Measurement Company, LLC

Norman F Marsh

Scott M Hewelt

Phillip P Fleckenstein

William T Cruickshank

Robert T Eichberger

Randall J Regentin

Michael C Torzewski

John R Schutt

Bruce W Campbell

A system for point-level detection of material within a vessel includes a transmission line probe adapted to be mounted to a wall of the vessel so as to extend within the vessel for contact with material when the material reaches a preselected level within the vessel. Electronics are operatively coupled to one end of the probe for launching microwave energy along the probe. The electronics are responsive to a change in microwave energy reflected from the free end of the probe within the vessel when the material is in contact with the probe, employing time-domain reflectometry techniques, for indicating that the material is in contact with the probe. This change in reflected microwave energy may comprise a change in phase or, more preferably, a change in apparent length of the probe resulting from contact with material having a higher dielectric constant than that of air when air surrounds the probe. The electronics preferably are also responsive to a decrease in apparent length of the probe for indicating a failure condition at the transmission line probe or electronics.

Material level sensing

A system for measuring the level of the interface between gasoline and water in an underground gasoline storage vessel includes an electronics enclosure from which a transmission line probe extends for contact with the gasoline and water within the vessel. The transmission line probe carries a reflection target disposed at a fixed known position with respect to the electronics enclosure, and at a position normally to be covered by the gasoline. Electronics within the enclosure employ time-domain reflectometry techniques to determine the position or level of the air/liquid surface of the gasoline, and to obtain an apparent position reflection measurement from the target disposed within the gasoline. Since the actual distance from the electronics to the reflection target, as well as from the target to the bottom of the vessel, are predetermined and known, and the level of the air/gasoline interface has been determined, the distance between the air/gasoline interface and the target is determinable, and a compensation factor related to the dielectric constant of the gasoline can be determined. Time-domain reflectometry is employed in conjunction with this compensation factor to determine the true level of the gasoline/water interface beneath the reflection target.

Material interface level sensing

Apparatus for indicating level of material in a vessel that includes a probe for placement in the vessel at a position corresponding to a desired height at which material level is to be detected. Electronic circuitry is coupled to the probe, and is responsive to operating characteristics of the probe for sensing a change of such operating characteristics between a first operating characteristic at which material is spaced from the probe, and a second operating characteristic when material is adjacent to the probe. The electronic circuitry is contained within a closed housing mounted on the probe, and is connected to a source of electrical power positioned remotely of the vessel. A pair of status lamps are positioned on the housing, and are coupled to the electronic circuitry for respectively indicating application of electrical power to the circuitry and detection of one or the other of the operating characteristics at the probe. A reed switch is positioned within the housing, and is responsive to juxtaposition of a magnet externally of the housing for simulating one of the operating characteristics of the probe independently of actual material level at the probe.

Material level indicating apparatus with status light and external test

A system for measuring level of liquid material in a containment vessel that includes a hollow conduit composed of a first conduit section having an upper end coupled to a pressure sensor and a lower end disposed within the vessel. A second conduit section is coupled to the lower end of the first conduit section and extends downwardly therefrom at least to a minimum material measurement level within the vessel. The second conduit section has a vertical height coordinated with the maximum desired material measurement level within the vessel such that pressure of air captured within the first conduit section at such maximum material level prevents entry of the liquid material into the first conduit section. The cross sectional area of air flow within the second conduit section is at least ten times, and preferably at least sixteen times, greater than the cross sectional area to air flow within the first conduit section. Thus, the volume of air captured within the air column formed by the first and second conduit sections is minimized, thereby minimizing the effects of temperature-induced fluctuations of column air pressure. On the other hand, liquid level within the air column remains at all times within the conduit section of larger diameter, thereby reducing the likelihood of clogging of the small-diameter conduit section due to sediments or the like carried by the liquid.

Liquid level measurement system

A photo-optical coupler is connected to a shaft to provide a series of electronic pulses at a frequency corresponding to rotational velocity of the shaft. Apparatus electronics is responsive to frequency of such pulses for indicating a low speed alarm condition when such frequency is below a preselected threshold. The apparatus electronics includes a digital counter that is set to a first preselected count upon occurrence of each of the shaft rotation pulses, and which is thereafter decremented between the shaft rotation pulses. A low speed alarm condition is indicated if the counter reaches a count of zero prior to a succeeding shaft rotation pulse. In the preferred embodiment, the counter is decremented by an oscillator having a clock frequency coordinated with the first preselected count so as to activate the alarm when rotational velocity of the shaft decreases to a predetermined threshold percentage of a nominal rotational velocity of the shaft.

Shaft rotation monitoring apparatus

A system for indicating the level of material in a vessel as a function of material capacitance comprising a resonant circuit including a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An oscillator has an output coupled to the resonant circuit and to a phase detector for detecting variations in phase angle as a funciton of probe capacitance. Level detection circuitry is responsive to an output of the phase detector and to a reference signal indicative of a level of material for indicating material level as a function of a difference between capacitance at the probe and the reference signal. In the preferred embodiments of the invention disclosed, an automatic calibration circuit adjusts the resonance characteristics of the parallel resonant circuit in a predetermined or preprogrammed manner during a calibration operation to a point indicative of the predetermined reference material level. A timer measures the duration of the automatic calibration operation for indicating conditions at the probe, such as the amount of material coated onto the probe. A reed switch is positioned adjacent to the cover of a housing which encloses the electronics and is responsive to variations in magnetic flux from externally of the housing for indicating a calibration operation without removing the housing cover.

Capacitance-type material level indicator

Apparatus for indicating the level of flowable material in a storage bin comprising a motor mounted within a protective enclosure and coupled by a shaft to a paddle disposed within the bin to engage material contained therein. When the material reaches the level of the paddle, drag on the paddle causes the motor to rotate within the enclosure and thereby to activate switches disposed within the enclosure for indicating material level. A spring is mounted between the enclosure and the motor such that the spring urges the motor to both the switch-activating and the switch-deactivating positions in turn, and must be urged over center to permit motion of the motor in either direction between such positions.

Growing community of inventors

Port Huron, MI, United States of America

Norman F Marsh