Flow Meter Assembly, Gate Assemblies and Methods of Flow Measurement

A tilt lift gate assembly including a gate member which can be raised and lowered from a vertically closed position through to a substantially horizontal disposition, said gate member being pivotally mounted at the top end thereof to a mechanism for pulling said gate member inwardly from the vertically closed position to the substantially horizontal disposition and at least one extension projecting from said gate member with a pivot point at the end of said at least one extension, said pivot point co-operating with a downwardly angled guide means whereby movement of said gate member does not cross said downwardly angled guide means.

A method of measuring fluid velocity in a pipe or open channel, said method including the steps of:

• providing a timing circuit which includes a first circuit having at least one upstream acoustic transducer and a second circuit having at least one downstream acoustic transducer, measuring the time delay in detecting the acoustic signal from said at least one upstream acoustic transducer to said at least one downstream acoustic transducer from said first circuit, measuring the time delay in detecting the acoustic signal from said at least one downstream acoustic transducer to said at least one upstream acoustic transducer from said second circuit, measuring the time delay in said first circuit when said at least one upstream acoustic transducer is bypassed in said first circuit, measuring the time delay in said second circuit when said at least one downstream acoustic transducer is bypassed in said second circuit, and calculating the fluid velocity using said measurements.

An acoustic flow meter for a pipe, said assembly including at least three pairs of acoustic transducers, each pair of said acoustic transducers located on opposing sides of said pipe and offset longitudinally along said pipe to provide upstream and downstream transducers, each pair of acoustic transducers, in use, having their acoustic paths intersecting at a point along the axis of said pipe to provide redundancy in measuring flow through said pipe if one of said acoustic transducers should fail.

A method of measuring acoustic transit times in an open channel or river, said method including the steps of:

• providing a first circuit having at least one upstream acoustic transducer on one side of said open channel or river and a second circuit having at least one downstream acoustic transducer on the opposite side of said open channel or river, said first and second circuits including respective timing circuitry which are not synchronised with one another, each of said timing circuits measuring their respective signal transmit and receive events, at least one of said first or second circuits including an RF or laser to provide synchronising signals between said first and second circuits, an RF or laser synchronising signal is transmitted between said first and second circuits prior to an acoustic signal transmitted from one of said acoustic transducers between said first and second circuits whereby said RF or laser synchronising signal allows synchronisation between the respective timing circuitry of said first and second circuits of said acoustic signal.