Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A moisture tester is provided for testing a sample of feed of the silage, haylage, and like compressible variety. The tester includes a chamber for receiving a feed sample. A compressible piston compresses the feed sample in the chamber to a predetermined density to provide accurate, reliable, reproducible results. The chamber comprises spaced electrodes constituting a capacitor such that the dielectric constant of the capacitor is modified in accordance with moisture within the feed sample. A circuit functionally including the capacitor develops a signal in accordance with the moisture content of the sample. A readout, responsive to the circuit signal, provides a visual indication of the feed sample moisture content. A circuit trigger is automatically operated by the compression exerted upon the feed sample to start circuit operation and provide the feed sample moisture content readout.

Abstract: A moisture tester for grain and like materials is disclosed. The tester includes a walled test chamber including spaced apart electrodes which form an electrical coaxial capacitor, the electrodes being located so that the dielectric constant of the capacitor is modified in accordance with the dielectric constant of a test material sample introduced into the test chamber. To limit the volume, and to configure and pack the volume of test material introduced into the tester in a predetermined way, a funnel arrangement is provided at the tester top. A lower portion of the funnel directs inflowing grain over an axially aligned, centrally located finger which forms one of the electrodes. A pour spout is provided for pouring test sample material from the test chamber after test completion.

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: A survey recorder for measuring electrical loads and providing a magnetic tape record of data with time reference signals in format capable of providing computer compatible information. The data recording circuit utilizes a light emitting diode with a phototransistor to determine each quantum measurement by the meter, and a trigger circuit driven by the phototransistor feeds a solid state divider circuit which is programmable to provide various I/O pulse ratio outputs to the data recording head. A power outage circuit detects outages which are greater than a predetermined duration and provides distinctive pulses to a time recording circuit to effect a recognizable format on the magnetic tape which identifies the power outage.