Abstract: A microwave waveguide is presented which includes a gas tight seal which provides pressure isolation between two portions of the waveguide. In accordance with an important feature of this invention, an upper flange includes a threaded axial opening for receiving and retaining a threadably mated dielectric filling material. If the thread pitch is small relative to the signal wavelength, the threaded section has essentially the same electrical characteristics as a smooth waveguide. The resulting structure provides an economical and practical method of retaining a solid dielectric filling material in a waveguide against high pressure without changing the effective diameter of the waveguide. In accordance with another feature of this invention, a novel high pressure seal is provided between the upper and lower flanges in the area surrounding the threaded axial opening.

Abstract: A method and system for monitoring the level of flowable material contained in a transportable vessel that utilizes microwave gauging technology. The system includes a microwave lens/seal assembly, a microwave transceiver assembly, a controller/processor assembly and a computer. The lens/seal assembly is permanently secured to the vessel. The microwave transceiver assembly is adapted to be releasably attached to the vessel. The controller/processor assembly and the computer may be located at a loading/unloading facility.

Abstract: A device is provided for enabling the signal generated by a sensing device to be presented which is representative of the property sensed of a flowing material over a conveyor, or the like. The output is presented for observation and/or as a usable input to control means responsive to the sensed property. A pair of signals, one with a slow time constant, the other with a fast time constant, is derived from the sensing device signal. An output signal is in turn derived from one of the two signals, normally the slow. From the event rate in the sensing device, the expected statistical deviation is computed and utilized as the threshold of divergence of the pair of signals. When the divergence exceeds the threshold, the fast signal is switched to be the same value as the slow signal so that no perceptible perturbation appears in the output and the output signal is derived from the fast signal.

Abstract: An apparatus for monitoring the level of material in a plurality of hoppers or bins includes a radiation source and sensor associated with each hopper. Each sensor generates an output signal representing the incidence of radiation passing through the material in the respective hopper. The sensor output signals are supplied to individual sample/hold circuits where they are temporarily stored. A central control circuit cyclically reads the stored signals from the sample/hold circuits and then generates a reset signal to clear the sample/hold circuits. The central control circuit compares the sum of the sensor output signals for each sensor over a predetermined time interval with at least one reference signal representing a predetermined material amount to generate a status signal for each hopper. A plurality of indicator circuits are responsive to respective condition of the status signals for visually and/or audibly indicating to an operator the status of the material level in the associated hopper.

Abstract: A method of placement of transducers on a pipe in positions where their beam axes intersect a point on the locus of points where the incremental flow is equal to the average flow is shown and described.

Abstract: A coupling device for attachment of a sonic doppler flowmeter to pipes or conduits is shown and described. In this coupling, a temperature compensated liquid wedge is used to couple the transducer to the wall of the pipe or conduit, and means are shown and described for eliminating bubbles from the liquid wedge region.

Abstract: In a switching circuit for controlling the level of material in a container, a first counter accumulates pulses generated at a rate inversely related to the level of the material up to a first predetermined total. A second counter accumulates clock pulses up to a second predetermined total representing a fixed counting interval. The counters are connected in a race circuit wherein the one to reach its predetermined total first resets both counters and controls the race circuitry. The first counter sets a control circuit to indicate a low level condition or to activate an alarm, and the second counter resets the control circuit to indicate a high level condition. After the control circuit has been set by the first counter, the race circuit is responsive to a third predetermined total of the first counter, less than the first predetermined total, representing, for example, a level to which a container is to be filled.