Patent ID: 6098467
Filing Date: 2000-08-08
Classification: G01F

Abstract:
An acoustic fluid flow meter comprising;an acoustic transmitter and receiver arrangement disposed relative to a flowing medium, said acoustic transmitter and receiver arrangement including a first element acting as a first transmitter and a first receiver operable alternately, said first transmitter emitting downstream acoustic pulses into said flowing medium, propagating downstream relative to said flowing medium, and said first receiver receiving said downstream acoustic pulses after propagation through said flowing medium, and second element acting as a second transmitter and a second receiver operable alternately, said second transmitter emitting upstream acoustic pulses into said flowing medium, propagating upstream relative to said flowing medium, and said second receiver receiving said upstream acoustic pulses after propagation through said flowing medium, said acoustic transmitter and receiver arrangement emitting respective signals into said flowing medium, the respective signals identifying when said downstream acoustic pulses are emitted, when said downstream acoustic pulses are received, when said upstream acoustic pulses are emitted and when said upstream acoustic pulses are received;a timer connected to said acoustic transmitter and receiver arrangement, said timer measuring a downstream transit time of said downstream acoustic pulses and an upstream transit time of said upstream acoustic pulses from the respective signals; andan error signal indicator in said timer, supplied with said downstream transit time and said upstream transit time, said error signal indicator deriving a derived value from said downstream transit time and said upstream transit time and emitting an error signal indicatinga false flow reading when said derived value differs from a control value by a predetermined amount.