ADS Environmental Services FlowShark Pulse QR 775004 A1 - Manual (Page 78)

Installation 6-33
Additional Information Concerning Control Systems
Determine the distance between the flow velocity sensor and the corresponding
control slide valve based on the default flow value, nominal diameter, and
preliminary pressure. This distance should be at least 3 times the internal diameter of
the pipe; however, a distance of up to 5 times the internal diameter is preferable,
when possible.
Flow velocities in the control distance should not fall below 0.98 feet per second
(30cm/s) under typical flow conditions to ensure adequate detection.
When using an air-ultrasonic sensor, calculate the required dome height according to
the maximum preliminary pressure.
Please note when using ADS air-ultrasonic sensors:
Minimum dome height [mm] = 350 mm (13.78 inches) + x • 40 mm (1.57 inches)
x =
maximum impound pressure in [m] upstream of
control slide valve
The slide valve should have exactly the same inside diameter as the incoming and
outgoing pipes. Always avoid hydraulic jumps, ledges, weld seams, rising flange
densities, and other structures when choosing a measurement location.
Install pipe insertion sensors slightly off center when sludge and/or silt are present.
Measuring flow depth with the pipe insertion sensor is not possible
when the sensor is not installed at the bottom center of the pipe.