Patent ID: 6477900
Filing Date: 2002-11-12
Classification: G01F

Abstract:
A fluidic gas metering system producing a low pressure drop when interposed in a line running from a gas source to a user site, the gas being supplied to the site via the system in a broad flowrate range defined by a low flowrate band in the lower portion of the range, a medium band in the middle portion and a high flowrate band in the upper portion thereof, said system comprising:an input chamber into which is fed a stream of pressurized gas derived from said source; an output chamber from which the gas stream is supplied to said user site; a first channel intercoupling the input chamber to the output chamber defined by a first fluidic generator through which the gas stream is flowable operative only when the gas stream has a flowrate in the low band to yield periodic electrical pulses having a repetition rate proportional thereto; a second channel intercoupling the input chamber to the output chamber defined by a second fluidic generator operative only when the gas stream has a flowrate in the medium band to yield periodic electrical pulses having a repetition rate proportional thereto; a third channel intercoupling the chambers defined by a bypass passage operative only when the flowrate of the gas stream lies in the high band, the third channel then acting to divide the gas stream into a minor component which is bypassed thereby, and a major component which flows through the second fluidic generator in the second channel and has a flowrate lying in the medium band; metering means including a processor coupled to the first and second generators to process the electrical pulses yielded thereby during operation of the system to meter the flow of gas in the low, medium and high bands and to totalize the pulses to provide accurate readings of the gas consumed by the user throughout the entire range; and means to indicate said readings.