Augmented surface sensor for measuring flow velocity

A flow velocity measurement system for measuring flow in an influent pipe which may become partially or fully filled with fluid, said system comprising:

• a first velocity measurement system, said first velocity measurement system for mounting at the top of the pipe, said first velocity measurement system transmitting a first signal and receiving a first reflected signal resulting from interaction with a surface of the fluid;
• said first reflected signal being processed to determine a first flow velocity;
• a fluid ultrasonic velocity measurement system, said fluid ultrasonic velocity measurement system transmitting a second ultrasonic signal and receiving a second reflected ultrasonic signal resulting from interaction with particles within the fluid;
• said second reflected ultrasonic signal being processed to determine a second Doppler shift frequency related to a second flow velocity;
• said first velocity measurement system directed to sense upstream of a location of said fluid ultrasonic velocity measurement system to avoid flow disturbance caused by said fluid ultrasonic velocity measurement system;
• and
• a communication interface configured to report said first flow velocity and said second flow velocity to a data processing facility.

A method for measuring fluid flow velocity in a pipe which may become partially or completely filled with fluid, the method comprising the steps of:

• providing a first velocity sensor for mounting at the top of said pipe, said first velocity sensor interacting with a surface of said fluid to determine a first flow velocity;
• providing a second velocity sensor, said second velocity sensor interacting with particles or flow features at the surface or in the body of said fluid to determine a second flow velocity;
• directing said first velocity sensor for sensing said fluid upstream of a location of said second velocity sensor to avoid flow disturbance caused by said second velocity sensor;
• determining a selection criterion for selecting said first flow velocity or said second flow velocity;
• and
• selecting said first flow velocity or said second flow velocity based on said selection criterion.

A method for measuring flow rate in an influent pipe which may become partially or completely filled with fluid, the method comprising the steps of

• verifying a condition of said pipe as having sufficient section of straight length and uniform cross section and freedom from flow disturbances;
• installing flow measuring equipment comprising a first velocity sensor;
• installing said first velocity sensor at the top of said pipe and directed upstream, said first velocity sensor observing upstream of any flow disturbance introduced by the installation of said first velocity sensor;
• said first velocity sensor for interacting with a surface of said fluid for determining a first flow velocity.