Ioniser type gas meter having modulating electrode downstream of ioniser

摘要

A gas meter gas a conduit for passage of a gas flow; an ioniser arranged to ionise the gas flow in the conduit; a modulating electrode structure arranged for modulating the ion distribution in the ionised gas flow; and at least a detecting electrode structure downstream of the modulating electrode structure arranged for detecting the modulated ion distribution in the ionised gas flow. The modulating electrode structure is arranged downstream of the ioniser and is configured to generate an electrical field which is substantial in a parallel to the direction of the gas flow.