Abstract: An apparatus provides flow-representing signals in response to orbiting of a body which passes a sensor and moves along a circular orbit around the flow path, the orbiting body being supported by a spindle that slants relative to the axis of the flow path.

Abstract: The disclosed orbital ball flow detectors have an exposed ball-sensing electrode near or along the path of the orbiting ball, and a return electrode. The ball's cross-section is much larger than the sensing electrode, which is closely over-shadowed by the ball as it orbits past the electrode. Unusually large signals are provided when the ball is of insulation and the flow to be monitored exhibits some electrical conductivity. Where the ball orbits along a conductive track and is of metal, it acts as a switch when oribiting past the sensing electrode.

Abstract: Flow monitors are disclosed for liquid like tap water having limited electrical conductivity, including a flow sensor and a circuit connected to electrodes in the flow sensor for producing flow-representing signals. Vanes of a flow-activated rotor made of insulation displace part of the pattern of current paths between the flow-sensor's electrodes. Circuits connected to the electrodes include a d-c or a-c excitation source and an impedance in series with the electrodes for providing amplitude-varying signal output. The steady-state excitation voltage at the electrodes is maintained constant despite diverse resistivities of various liquids, and the series impedance is much higher than the resistance between the electrodes. D-c excitation promotes economical utilization of a long-life circuit-energizing battery. With d-c excitation, the positive electrode is of platinum or other material that serves as an electro-chemically inert anode in the liquid.

Abstract: The disclosed apparatus for sensing the flow of liquid along a passage includes a turbine-type rotor formed of high-resistivity insulation and supported coaxially in the passage. The rotor has spiral vanes distributed about a core. A stator upstream of the rotor provides a spiralling flow pattern in the zone of the rotor. The stator has vanes that spiral in the same direction as the rotor's vanes but at a lower pitch. An electrical sensor provides a varying signal representing the rotation of the rotor. The output signal waves are accurately proportional to the flow over an unusually wide range of flow rates. The electrical sensor includes electrodes exposed to the flow passage, a sensing electrode that is wider than the thickness of a rotor vane and a metal pipe that serves as a companion electrode. Successive pairs of rotor vanes span the sensing electrode at intervals as the rotor turns, periodically acting as barriers that reduce conduction through the liquid in the passage.

Abstract: The disclosed apparatus for sensing the flow of liquid along a passage includes a turbine-type rotor formed of high-resistivity insulation and supported coaxially in the passage. The rotor has spiral vanes distributed about a core. A stator upstream of the rotor provides a spiralling flow pattern in the zone of the rotor. The stator has vanes that spiral in the same direction as the rotor's vanes but at a lower pitch. An electrical sensor provides a varying signal representing the rotation of the rotor. The output signal waves are accurately proportional to the flow over an unusually wide range of flow rates. The electrical sensor includes electrodes exposed to the flow passage, a sensing electrode that is wider than the thickness of a rotor vane and a metal pipe that serves as a companion electrode. Successive pairs of rotor vanes span the sensing electrode at intervals as the rotor turns, periodically acting as barriers that reduce conduction through the liquid in the passage.

Abstract: Energy transmitted to a load in a fluid medium is measured utilizing a probe having an elongate heat transmitter that includes a sensing tip at one end, a heat exchanger at its opposite end, a thermal impedance forming at least a segment of the heat transmitter, and temperature sensors spaced apart along the impedance. The temperature of the sensing tip is maintained different from that of the sensed fluid. A read-out is responsive to the temperature sensors and it is calibrated in terms of the energy content of the fluid flowing in the sensed passage. Corrections for various factors of error are incorporated in the read-out. A relative simple yet reasonably accurate measure is made of the energy in steam, where the heat exchanger of the probe is a passive heat dissipator.

Abstract: The disclosed apparatus includes novel fluid-flow detectors wherein a ball orbits along a circular track inside a wall that bears external piston-mode piezoelectric transducer means, the wall being of either plastic or metal. In one form of orbital-ball flow detector, the linear range of flow-versus-orbiting frequency is extended to lower flow rates by providing an inner track of the ball on a bearing member that is rotatable by the orbiting ball. The range of flow rates is also extended for an axial-flow detector having an orbital ball or a turbine-type rotor as the fluid-activated element by providing multiple subdivision passages having valves that close at successively lower main-passage flow rates, the subdivision passages having flow detectors whose outputs are combined to provide output that represents flow in the main passage.

Abstract: The disclosed orbital ball flow detectors include a photoelectric ball sensor applicable to both axial-flow and toroidal forms, wherein reflection occurs at the ball. Also disclosed are photoelectric ball sensors of both the transmission and reflection types in which the light path extends through pellucid material of the passage means that forms a track against which the ball bears as it orbits. There may be a swirl in the flow pattern of the fluid; and then multiple pairs of orbital ball flow detectors, each carrying part of the total flow and having mutually opposite orbit directions, provide improved accuracy.

Abstract: The disclosed flow sensor includes a pipe segment forming a flow passage, having vanes that cause the entering liquid to spiral in passing through a flow-detection zone. An orbital ball is captive in the zone, orbiting in proportion to the flow velocity. A localized capacitive flow detector and a companion capacitive electrode sense the orbiting of the ball. The capacitive electrodes are coupled to the frequency-determining portion of a feedback-stabilized oscillator whose output is modulated each time the ball travels past the sensing electrode. A feedback-stabilized oscillator having a sensing coil is similarly modulated by the effect of a vaned rotor moving past the coil. Different forms of feedback having a long-time-constant maintain high sensitivity of the oscillator to the effect of the flow-activated device.

Abstract: The disclosed flow-detecting apparatus involves gating of phase-related excitation and sensed signals from electrodes close to a flow-activated tracker in a liquid passage. A high gain comparator provides peak-limited signals to the phase-comparison gate. In one form, a pair of excitation electrodes are symmetrical in relation to a single sensing electrode. That electrode supplies a sensed signal to one comparator input, the other comparator input having fixed bias. In another form, a pair of sensing electrodes are disposed in an excitation pattern between a localized excitation electrode and a metal pipe that forms the passage and acts as a second excitation electrode. The sensed signals reach respective input terminals of a high-gain comparator and it responds to the difference between the inputs. Other configurations of the electrodes and their excitation are disclosed, including one that promotes rejection of common-mode spurious signals.

Abstract: Disclosed acoustic flow sensors include a cylindrical wall that forms a cylindrical flow passage, a flow activated rotor in the passage, and an electrical generator for developing flow-representing signals. In probe type flow sensors, the cylindrical wall is a shroud surrounding the rotor and forming a flow metering passage within a larger main passage, and the disclosed one or two piezoelectric device is/are decoupled from the fluid outside the shroud by sound-deadening material and coupled to the fluid within the shroud. For both probe-type flow sensors, and in-line flow sensors, the cylindrical wall is stressed and subjected to arcuate dimension change by piezoelectric device(s) of the radial-mode type bonded to the cylindrical wall.

Abstract: The disclosed apparatus includes a heat meter and a flow meter. The heat meter includes means for delivering trains of pulses to a heat register, the pulses per train being proportional to the temperature difference between fluid inlet and outlet passages of heat exchange means, and the recurrence rate of the pulse trains being determined by a flow sensor. A visual indicator of the pulse trains facilitates zero-difference adjustment of the temperature sensors when they are both at the same temperature. Compensation for variations in the specific heat of the fluid and temperature-related inaccuracy of the flow sensor is effected by non-linear frequency adjustment of an oscillator that generates the pulses. In a flow meter (omitting the temperature-difference circuit) compensation for temperature-related inaccuracy of flow-sensors is effected correspondingly.

Abstract: The disclosed flow sensors involve rotor-bearing probes proportioned for entry through a hole in a pipe. By omitting flow-straightening vanes, the rotors can be relatively large. Multiple rotors distributed across the flow passage, especially one or more pairs of oppositely rotating rotors, have respective rotation sensors whose outputs are combined for averaging out the varied effects of the flow on the rotors. The rotation sensors produce trains of pulses that are converted to narrow spikes before being combined.

Abstract: The disclosed apparatus includes a heat meter and a flow meter. The heat meter includes means for delivering trains of pulses to a heat register, the pulses per train being proportional to the temperature difference between fluid inlet and outlet passages of heat exchange means, and the recurrence rate of the pulse trains being determined by a flow sensor. A visual indicator of the pulse trains facilitates zero-difference adjustment of the temperature sensors when they are both at the same temperature. Compensation for variations in the specific heat of the fluid and temperature-related inaccuracy of the flow sensor is effected by non-linear frequency adjustment of an oscillator that generates the pulses. In a flow meter (omitting the temperature-difference circuit) compensation for temperature-related inaccuracy of flow-sensors is effected correspondingly.

Abstract: In the disclosed apparatus, flow of fluid in a pipe is sensed by directing acoustic signals at a fluid-metering rotor in the pipe. One or more transducers are used for emitting an acoustic signal and receiving acoustic reflections. A flow-representing signal is derived that varies with the attitude of the rotor in relation to the transducer(s).

Abstract: The disclosed apparatus comprises a sheet-metal strap having a strip portion that can be threaded through a slot in the strap so that a loop is formed to encircle a temperature sensor having pipe-encircling portions extending oppositely from the loop generally as a "figure-8", providing parallel heat conduction paths between the pipe and the temperature sensor. Extremities of the strap can be drawn toward each other, thereby developing tension about the temperature sensor and the pipe; and the extremities can be folded with each other as a means for tensioning the sheet-metal member against the temperature sensor and the pipe and for securing the strap in place under tension.

Abstract: The disclosed sensors convert flow of liquid along a passage into electrical signals to represent rate or volume of the liquid flow. Vanes of a rotor are driven by the liquid so as to sweep past plural excitation and sensing electrodes that pass current through the liquid and sense the changing impedance caused by the vanes. The impedance of the liquid portion of the sensor circuit is modified at a frequency representing the travel of rotor vanes past the electrodes.

Abstract: Apparatus and a method are described for measuring heating and/or cooling of air or other fluid that occurs between an inlet and an outlet, one being a low-temperature passage and the other being a high-temperature passage. Heat is supplied to a temperature sensor in the low-temperature passages sufficient to raise that sensor to the temperature sensed in the high-temperature passage where the sensor of the low-temperature passage is cooled both by the fluid temperature and its mass-flow rate, and the supplied heat is measured.

Abstract: The disclosed rotation sensors involve a first poled magnetic device that rotates with the part whose rotation is to be sensed, a second poled magnetic device coaxial with the first, magnetically induced to rotate in unison with the first magnetic device, and a sensing element disposed between the circular paths of the poles of the magnetic devices. In one form, the sensing element is a Hall-effect device. In a second form, the sensing element is a winding that provides both a rotation signal and electrical energization for local circuit equipment responsive to the signal.

Abstract: The disclosed apparatus includes separate "heat" and "cool" registers and selective switching means that connects the output of a thermal energy computer to one register or the other in accordance with use of a room heat-exchanger to produce heating or cooling. The switching means also interchanges the connections of inlet and outlet fluid temperature sensors in the computer corresponding to heating or cooling operation of the system. The temperature sensors control the switching means for automatic selective operation. The flow meter is in the outlet of the room heat-exchanger, to undergo a minimized range of temperatures under all conditions, and the computer provides correction for temperature-induced error of the flow meter.