UA92923C2 - Gas-meter - Google Patents

Abstract

A gas meter comprises a conduit (1) for passage of a gas flow A and an ioniser (2) arranged to ionise the gas flow in the conduit (1). A modulating electrode structure (4) downstream of the ioniser modulates the ion distribution in the ionised gas flow. A first detecting electrode structure (8) and a second electrode structure (9) downstream of the modulating electrode structure 4 detect the modulated ion distribution in the ionised gas flow. The modulating electrode structure (4) and the detecting electrode structures (8, 9) can be configured to generate an electrical field having at least a substantial component parallel to the direction of the gas flow. The modulating electrode structure (4) and the detecting electrode structures (8, 9) can comprise a pair of electrodes (5, 6, 10, 11), each having a plurality of apertures defined therein for passage of the gas flow. The modulating electrode structure (4) can be arranged to capture ions of one polarity, to generate an ionised gas flow comprising a majority of ions of the opposite polarity, in which case the detecting electrode structure can comprise at least one electrode (11) connected to a source of charge. Movement of the ionised gas flow relative to the electrode causes a redistribution of charge in the electrode, which generates a current indicative of the ion distribution between the electrode (11) and the charge source. The various arrangements provide a gas meter that can operate with a modulating voltage of less than (10) volts and is therefore suitable as a domestic gas meter.