Lucas Industries Limited

Kenneth S Evans

Charles Peter Cockshott

Christopher M Pacaud

A corona-discharge type gas flow meter includes a discharge electrode, and a split collecting electrode, the collecting electrodes are connected to input amplifiers which act as current-to-voltage converters receiving a reference signal from an integrator acting to integrate the sum of the outputs of the input amplifiers. The output of the integrator is used to control an EHT supply for the discharge. An output amplifier provides a flow signal by running the signal from one input amplifier, from a variable offset nulling signal derived via an amplifier from the integrator and a fixed offset nulling signal from a potentiometer.

Gas flow meters

Apparatus for measuring the mass flow of a fluid comprises a hollow collector electrode assembly through which the fluid flows. The collector electrode assembly includes a central electrode disposed between and insulated from first and second outer electrodes. An ionizing electrode comprising a length of conductive wire is supported coaxially within the central collector electrode. A voltage source is provided for applying between the ionizing electrode and the collector electrode assembly a potential difference sufficient to ionize the fluid. The ions thereby produced at the ionizing electrode migrate towards the central collector electrode but are displaced in the direction of fluid flow by an amount dependent upon the mass flow of the fluid. A differential amplifier is responsive to the number of ions migrating to the outer collector electrodes to provide a measure of the displacement of the ions by the fluid flowing through the collector electrode assembly.

Measurement of the mass flow of a liquid

A power supply circuit includes an operational amplifier oscillator, a buffer amplifier and a diode pump connected to provide a negative output relative to the more negative of two supply rails. The supply terminals of the operational amplifier are connected to one supply rail and the output of the diode pump respectively, so that when the circuit is first connected to the supply the operational amplifier is initially connected between the rails through the intermediary of the diodes of the diode pump.

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Blackpool, United Kingdom

Kenneth S Evans