Improvement of accuracy in large sewer mean flow measurements using an array of Doppler transducers

The objective of the work was to produce a self-controlled, battery powered instrument that could produce velocity profile information across the section of a large sewer. The Doppler Transducer Velocity Array System was produced to meet this and testing has shown that the system functions as designed. Field testing of the system showed that the accuracy of the results recorded was to within 10.9% of an independent propeller meter. The transducer beams were forced to cross at specific positions and thus it was known exactly where in the flow the velocity readings originated.