Abstract: Apparatus for measuring the rate of flow of a fluid in a conduit includes a receptor assembly arranged on the external surface of the conduit, and a removable external connector assembly including an electromagnet for establishing a magnetic field that extends transversely across the conduit, and a plurality of circumferentially arranged electrodes that are insertable into direct contact at their tips with the fluid in the conduit via sealable gland passages contained in the receptor assembly. A calibration adjustment arrangement is provided for adjusting the calibration factor of the flow signal processing system as a function of the conduit cross-sectional area. In a first embodiment, the glands are self sealable, whereupon the gland passages are automatically closed when the electrodes are removed therefrom.

Abstract: A flowmeter utilizing velocity at the surface of a fluid and lookdown level sensors is mounted within a manhole without requiring entry into the manhole by the installer. The velocity and level sensors generate first and second energy signal beams which are directed toward the same vicinity of the fluid surface which reflects the beams back to the sensors surface velocity signal representative of the velocity of scatters on the fluid surface is produced from the Doppler frequency shift between the directed and reflected first beam. This signal is modified to produce a mean velocity signal. A level signal is produced by determining the air space between the sensor and the fluid surface from the directed and reflected second beam and relating changes in the air space to changes in fluid level in accordance with the configuration of the pipe. Fluid flow can be calculated from the mean velocity and fluid level signals.

Abstract: An open-channel flowmeter is calibrated by the use of local velocity and level characteristics existing at a given site, as measured by the flowmeter itself. Stored reference relationships that have been either theoretically or experimentally derived are compared to the velocity level relationships at any particular site so as to determine a correction factor which is valid at that site so as to modify the sensed velocity to be an accurate approximation of the average velocity under those site conditions. A local velocity signal is modified so as to make it an accurate approximation of the mean velocity for open-channel flowmeters of the level/velocity type.

Abstract: An improved flowmeter sensor for measuring the level of liquid flowing in a conduit, pipe or open channel, characterized by an initially air-filled pressure transmitting passage which affords communication between a pressure port contained in the bottom of the sensor body, and a pressure transducer contained in the sensor body. The passage includes a vertical portion communicating at its lower end with the pressure port, and a horizontal portion connected with the transducer, whereby hydraulic pressure forces liquid into the passage to compress the air therein and thereby exert on the pressure transducer a pressure corresponding to the level of liquid in the conduit. The cross-sectional area and high surface energy of the material used to form the passage prevent liquid in the passage from migrating to the pressure transducer.

Abstract: An improved flowmeter apparatus and method for accurately determining the liquid flow rate in a conduit and the mass flow rate of selected pollutant components entrained in the flow stream characterized by injecting at least two trace materials into the flow stream at a plurality of locations and, after allowing adequate time for the trace materials to reach a downstream sampling location, collecting a plurality of samples of liquid from the flow stream containing the trace materials. By comparing the concentrations of the trace materials found in the sample, the degree of mixing of the trace materials in the flow stream, and hence the accuracy of the flow stream flow rate and pollutant component mass flow rate measurements, can be evaluated. Other injecting methods for more thoroughly mixing the trace materials with the flow stream are also disclosed.

Abstract: A method and apparatus for measuring fluid flow is characterized by compensating for temperature variations in the fluid level pressure transducer. The transducer is operated at a plurality of different combinations of pressure and temperature, and the drive and output voltages of the transducer are measured at each combination. A plurality of temperature coefficients are derived from the measured voltage and entered into a data logger for use in calculating flow.

Abstract: A liquid flowmeter and method for determining the velocity of flow of fluid in a conduit, including a sensor adapted for mounting in the bottom of the conduit, and including acoustic energy transmitting and receiving devices, an in-phase reflected Doppler energy signal detector connected with the receiving device, an anti-alias low pass filter for producing from the in-phase reflected energy a filtered signal, a digital-to-analog converter for digitalizing the in-phase signal to produce a sampled array, an accumulator for storing a first number (M) of mean zeroed power spectra from the sampled array, a zeroing device for zeroing a second number (K) of the initial samples of the power spectra, thereby to produce a first modified spectra, a median filter of rank R for filtering the first modified spectra to produce a second modified spectra, a limiting device for limiting the second modified spectra to produce samples limited to the upper portion of a range of amplitudes, thereby to produce a third modified spe

Abstract: A magnetic flowmeter includes a flow tube that is connected in fluid-conducting relation between a pair of axially spaced sections of a conduit, a first electrical connector being fixed to the outer surface of the flow tube and including first terminals electrically connected with spaced internal electrodes, respectively, that contact the fluid flowing through the tube. A second electrical connector is provided for separable connection with the first connector, which second connector includes an end-fire electromagnet for establishing a transverse magnetic field in the flow tube via the first connector, and second terminals for connecting the electrodes with a flow-indicating meter via the first terminals, respectively, and a cable. In order to calibrate the meter for use with a plurality of flow tubes having different internal cross-sectional dimensions, respectively, the first and second connectors are provided with cooperating size coding and decoding devices, respectively.

Abstract: A pump station flowmeter is disclosed including a sudden high inflow change detection circuit for eliminating from a series of emptying characteristic calculations taken over a period of time those measurements which are outside of a predetermined acceptance range. The wet well dimensions, level detector signals, clock signals and pump status signals are supplied as inputs to both a volume rate of change calculator and to the sudden high inflow change detector. In the event of an undesirable measurement, the sudden high inflow changes detection circuit operates a gate to isolate the volume rate of change calculator from the emptying characteristic calculator that calculates outflow. A flow integrator is provided for calculating volume per cycle from the volume rate of change signal, and an inflow calculator serves to produce inflow from the volume per cycle signal.

Abstract: An electromechanical flowmeter includes a coil arrangement located completely outside the fluid conduit for producing a magnetic field that extends concentrically about the longitudinal axis of the conduit, the portion of the field adjacent the inner periphery of the conduit being stronger than that adjacent the center of the conduit. First electrodes are mounted on the interior wall surface of the conduit within the magnetic field, and second electrodes are arranged at a location generally unaffected by the field. In the preferred embodiment, the second electrode is mounted on the interior wall surface outside the magnetic field in longitudinally-spaced relation relative to the first electrodes, whereby the provision of any flow-obstructing electrode within the conduit is completely avoided. In a non-preferred embodiment, the second electrode is mounted centrally with the conduit relative to the longitudinal axis thereof.

Abstract: A pressure level sensor for mounting a pressure transducer in a fluid flow channel. The sensor is characterized by an elongated wedge-shaped configuration wherein the width of the convex front wall portion is less than that of the rear wall portion which in turn is less than the length of the sensor. The side wall portions of the sensor each have concave surfaces, the radius of curvature of which is a function of the length of the sensor. At least one side wall portion contains a horizontal pressure port for communication with the pressure transducer. The front, rear, and side wall portions are tapered and curved vertically inwardly and terminate at a top wall portion. When the sensor is arranged on the bottom of the channel with the front wall portion facing upstream relative to the fluid flow, the velocity vector of the fluid flow is perpendicular to the direction of extension of the opening, thereby to minimize flow velocity effects on the pressure transducer.

Abstract: A flow meter for measuring the velocity of fluid flow in a conduit is disclosed, characterized in that an electromagnetic sensor probe is mounted within an opening contained in the conduit for generating electrical signals as a function of the velocity of fluid flow. The probe has a debris shedding head portion which protrudes into the interior of the conduit and includes an electromagnet for generating an electromagnetic field in the fluid, the axis of the field extending normal to the direction of fluid flow. The probe further includes a plurality of electrodes arranged beyond the poles of the electromagnet and adjacent the fluid for producing the electrical signals in response to the flow of fluid through the electromagnetic field. Signal processing apparatus is connected with the sensor probe for converting the electrical signals into a flow velocity output signal.

Abstract: A fluid flow rate meter is disclosed for measuring the flow of fluid in a partially filled conduit or channel, including an electromagnetic probe adapted for mounting in the conduit below the low water mark thereof to produce a sensed velocity signal, and a liquid height pressure transducer including an air tube having a bubble-producing opening adjacent the probe for generating a liquid height signal that modifies the sensed velocity signal to produce a resultant signal that corresponds with the average velocity of fluid flow, whereby a more accurate measurement of the rate of fluid flow is obtained. The average velocity signal is multiplied with a conduit area signal obtained from the height signal by a function generator circuit which takes into account the maximum diameter of the conduit (or maximum height of the channel). A percent flow signal is modified by a second function generator in accordance with the area of the conduit.

Abstract: Electromagnetic sensing means are disclosed for measuring the velocity of a current of fluid, such as water, characterized by the use of a spherical body containing electromagnetic means including a first coil for establishing a first magnetic field in the fluid in which the spherical body is submerged, and a plurality of pairs of peripherally mounted circumferentially spaced pairs of diametrically arranged electrodes which are contained in a common first plane normal to the axis of the first magnetic field, each electrode of the electrode pair protruding radially outwardly from the outer surface of the spherical body a common distance which is between 0.100 and 0.125 inch per inch of the diameter of the spherical body. In a two-axis embodiment, first and second orthogonally-arranged pairs of diametrically opposed electrodes are provided, together with detecting and indicating means for comparing the electrical signals produced across the electrodes of the electrode pairs, respectively.