Abstract: A measuring tube for a flowmeter and a process for making the measuring tube. The measuring tube is lined with a tubular lining of thermoplastic material, particularly PTFE or PFA, which comes into contact with the measured substance which flows through the tube. The ends of the tubular lining are flanged around end flanges of the measuring tube after the ends of the tubular lining have been plasticised by heating. The plasticised ends of the tubular lining are turned outward by more than 90.degree. and then forced into undercuts in the end faces of the end flanges. Upon cooling, the ends of the lining are in intimate contact with the end faces of the end flanges and the undercuts in the end faces.

Abstract: Device to measure the flowrate of a fluid flowing in a partially full line, such as a canal or open channel, with coils arranged above and below the partially full line to generate a magnetic field extending essentially vertically through the partially full line and with electrodes arranged opposite each other on opposite lateral walls of the partially full line. An excitation circuit excites the coils and an evaluation circuit processes the potential difference at the electrodes resulting from the magnetic field and the fluid flow to produce a flowrate proportional signal. The device is characterized by a bridge which spans the partially full line and on which the upper coil is positioned with the vertical axis of the upper coil extending through the central region of the bridge.

Abstract: A circuit for detecting faults in a magmeter system in which an electrically conductive fluid flows which is maintained at a reference potential. The circuit includes at least two electrodes in contact with the fluid. The electrode signals are conducted to the corresponding inputs of a measuring circuit. An alarm circuit is connected ahead of the measuring circuit. A difference in the magnitude of the values (+U.sub.S and -U.sub.S) of the electrode signals and/or non-symmetries in the noise content of the electrode signals and/or a disturbance in the high frequency signal (U.sub.G) in a loop which contains the electrodes and a high frequency producing generator causes an alarm to be activated.

Abstract: A weir is placed across a pipe section and an electromagnetic flow meter with multiple electrodes is located upstream of the weir. The liquid level and velocity of fluid in the pipe section are evaluated by the electromagnetic flow meter to determine flow rate.

Abstract: A liquid flow measuring system which, by means of a suitable timing sequence, is able to detect unbalanced voltage generation which occurs when the tube element through which the liquid is flowing is not completely full and, by means of a correction process, supplies an output signal which is proportional to the rate of flow. When the tube element is full, the system operates in the same way as a normal magnetically inductive flowmeter. If the level in the tube element falls, electrodes which are installed in the lower half of the tube element and other electrodes, if necessary, can be used exclusively or additionally to record the measured values. Moreover, with a view to improving the recording of measured values when the level falls below a specific limit, an arrangement of electromagnets, specially optimized for partially filled tube elements, can be activated instead of the normal arrangement of electromagnets.

Abstract: Fluid flowrate measuring apparatus in which magnet coils, positioned symmetrically about a pipe through which fluid flows, are excited to generate magnetic fields during four periods of an excitation cycle which are additive during the first period of excitation, opposing during the second period of excitation, additive during the third period of excitation in an opposite sense to that during the first period, and opposing during the fourth period of excitation in an opposite sense to that during the second period. Electrodes, which sense fluid flow through the magnetic fields, develop signals representative of fluid flow through the pipe during the four excitation periods and these signals are processed to develop a flowrate measurement signal.

Abstract: A data communications network in which multiple host processors are linked in a ring network by respective network interface processors or nodes includes circuitry in each of the nodes which aids in the implementation of a distributed resource locking scheme and a reliable multicasting system. The circuitry includes a packet generator which automatically generates specialized packets that are used to procure resource locks and to implement the multicast system. In addition, the node includes circuitry which may be used to modify the contents of a received packet and circuitry which automatically retransmits the packet onto the network. The node is controlled by a set of state machines which implement the resource locking and multicasting protocols. In addition, the nodes include circuitry which detects congestion in the node and in the network and acts automatically to relieve the congestion.

Abstract: This invention is concerned with packet switching techniques, protocols, networks, and equipment for use on a local area or wide area scale. Packets which include a fixed-length data field and memory offset field are employed so that packeting, block data transfer to contiguous memory and depacketing can be effected at the destination by hardware-mediated processes with minimal processor involvement. Multiple sessions can be readily handled by assigning addresses to multiple memory buffers at the destination. Thus, each packet carrying computer data provides three levels of addressing for its data segment corresponding to the destination node or device, the memory buffer for the data block being transfered and the memory location within that buffer into which the segment of data carried by the packet is to be placed. The equipment includes loop-based, collision-free packet switches in which packets are modified and re-circulated when a destination is busy.

Abstract: Apparatus for measuring the flow of a fluid medium which flows upward through a substantially vertically mounted tube section having a suspended body in the tube section. The vertical position of the suspended body depends on the intensity of the flow. Movement of a magnet, movable with the suspended body, is sensed by a unit which includes a Hall sensor and an electronic evaluation circuit, responsive to the Hall sensor output, develops an output signal corresponding to the flow of the medium.

Abstract: A UV lamp rack assembly usable in an ultraviolet ray wastewater treatment system, the rack including a horizontal hanger bar. When the assembly is installed in a channel through which a stream of wastewater to be treated is conducted, the bar is then supported above the channel in the flow direction of the stream. Depending from the bar at an upstream position is a vertical rod along which sleeves are pivotally mounted at spaced points thereon whereby each sleeve can be swiveled in a horizontal plane. Depending from the bar at a downstream position is a vertical conduit along which detachable lamp couplers are mounted at corresponding points, each coupler housing a lamp socket that is connected through the conduit to a power source. Extending between each sleeve and the coupler corresponding thereto is a lamp unit formed by a transparent protective tube enclosed at its upstream end and housing an elongated UV lamp whose terminal pins are at the downstream end.

Abstract: A flowmeter of the Coriolis type in which the fluid to be metered is conducted through a straight measuring tube attached at its inlet and outlet ends to fixed supports, whereby the tube is free to vibrate in a circular path as well as to torsionally oscillate. Actuator means are provided to excite the tube at a point intermediate the inlet and outlet ends, causing the tube to vibrate in a circular path. When fluid flows therethrough, the tube is subjected to Coriolis forces, causing it to torsionally oscillate in accordance with mass flow. A pair of sensors are disposed at respective points between the inlet and outlet ends of the tube and the excitation point to yield in response to the torsional oscillations, sensor signals which are applied to a processing circuit from which a measurement signal is derived that depends on the relative phases of the sensor signals, after averaging several circular vibrations to provide a mass flow readout.

Abstract: A mass flowmeter of the Coriolis-type in which fluid to be metered is conducted through a flow tube which is coiled to define a helix having a pair of identical measuring loops forming a double loop, on either side of which is an isolation loop. The fluid is admitted into the input of one isolation loop and is discharged from the output of the other isolation loop. The helix is concentric with a support structure having at one end a flow inlet to which the isolation loop input is affixed, and at the other end a flow outlet to which the isolation loop output is attached. A rigid bar parallel to the axis of the helix is joined to the junction of the measuring loops as well as to the respective junctions of each measuring loop and its associated isolation loop whereby the isolation loops then function as decoupling springs to effectively isolate the bar and the double measuring loop from external forces.

Abstract: An electromagnetic flowmeter in whose primary the fluid to be metered is conducted through a flow tube to intercept a composite magnetic field to induce therein a voltage which is picked up by capacitive metering electrodes. The composite field is formed by a low-frequency comparison field having a long period on which is superimposed a high-frequency switching field having a short period. The voltage from the capacitive electrodes is fed by way of a high pass filter to the input amplifier of a secondary whose amplified output is analyzed to provide separate components, one originating from the comparison field and the other from the switched field. An output signal is produced in accordance with the time phasing of these components, after compensating for the signal loss experienced in the filter by the comparison field component by means of a compensation voltage derived from the switched field component.

Abstract: An electromagnetic flowmeter whose primary includes a flow tube through which the fluid to be metered is conducted to intersect a magnetic field and thereby induce a voltage therein that is transferred to electrodes to produce an electrode signal as a function of flow rate, which signal includes a noise voltage. The electrode signal is applied to the input amplifier of a secondary whose output is fed to one input of a summing stage, the output of which is fed to a range amplifier that yields a test voltage, the input and range amplifiers producing offset voltages. To compensate for the noise and offset voltages, a compensation voltage is derived from the test voltage and applied to the other input of the summing stage. This compensation voltage is produced only when the test voltage exceeds a predetermined threshold value.

Abstract: A laser welding technique for joining two parts together, the parts having contacting faces which define an interfacial region. One part is permeable to a laser beam directed toward and focused on the interfacial region, the face of the other part having light-disruptive characteristics whereby when the beam impinges thereon, multiple internal reflections are produced within the interfacial region which trap the energy of the beam to generate sufficient heat to cause the parts to superficially melt and fuse.

Abstract: An ultrasonic, echo-ranging instrument for measuring liquid level, the instrument including a transducer dispoed at a fixed position directly above the liquid surface. The transducer is excited to emit periodic pulses which are intercepted by the liquid surface as well as by a reference point a fixed distance from the transducer to produce both reference and liquid echo pulses that are returned to the transducer and detected thereby. The respective transit times of the reference echo and the liquid echo pulses are determined, and the ratio between these transit times is computed to provide an output representing the level of liquid. To ensure accurate readings, the reference echo and liquid echo pulses from the transducer are fed to a single automatic gain control circuit whose operation is time shared.

Abstract: A mass flowmeter of the Coriolis-type having a primary wherein fluid being metered is conducted through a flow tube in the form of a double loop whose loops are excited by a driver to vibrate in phase opposition at the resonance frequency of the tuning fork. Because fluid passing through the flow tube is subjected to Coriolis forces, the vibrating loops are caused to torsionally oscillate in accordance with the mass flow of the fluid. A pair of sensors mounted on the respective loops sensor signals which are applied to a differential amplifier in a signal recovery system forming the secondary of the meter to produce an output voltage that is a function of mass flow. This output voltage is applied to the input of a microcontroller coupled to an indicator providing a reading of mass flow. The meter is calibrated so that at the resonance frequency under normal operating conditions it produces a reading proportional to mass flow.

Abstract: A differential pressure transducer of the capacitive type responsive to fluid pressure. The transducer includes a cylindrical body having insulating sections at either end provided with a planar end face and a concave cavity surrounded by an annular rim. The cavities communicate with each other through an internal duct in the body and are filled with a dielectric fluid. Covering each cavity and sealed to the surrounding rim is a diaphragm provided with a movable electrode which cooperates with a fixed electrode on the cavity surface to form a capacitor therewith whose value varies as a function of diaphragm deflection in response to an applied pressure.

Abstract: An industrial process control system in which an electronic controller acts in a controlled process subject to process "dead time" to maintain a process variable at a desired value. Applied as inputs to the controller are signals representing the process variable and a set point, the controller yielding an output signal that reflects the deviation of the process variable from the set point and acts to adjust a final control element in the system to cause the process variable to conform to the set point. To effect self-tuning of the controller, a microprocessor is provided which is responsive to the process variable signal and the output signal from the controller and functions while the controller is operating to identify in a discrete-time process model parameter-identifier the process dead time and the process parameters, and to compute tuned controller parameters, and to transfer the calculated controller parameters to the controller so that the controller can be tuned to prevailing process conditions.

Abstract: Computer graphics for an industrial process installation or other computer-controlled system in which the system is graphically displayed on the screen of the computer terminal. Each controllable element in the system, such as a valve, a control dial or a switch, is marked on the display by an action point. In order for an operator to select any desired action point on the display to carry out an action appropriate thereto, a cursor is provided which can be manipulated by a key matrix to occupy a position coinciding with any action point thereon. The key matrix is a three-by-three-matrix constituted by a home key surrounded by eighty arrow keys whose arrows are directed to the major axes of a compass rose. Only one action point can be selected at a time. The selected point then effectively becomes the compass center, the previously selected point being then de-selected.