ADS Environmental Services Model 3600 530002 A2 - Manual (Page 51)

4-18 ADS 3600 Flow Monitor O&M Manual
l Place the ring assembly into the upstream pipe as far as necessary to ensure a
good environment for flow measurement. The exact position of the ring varies
from site to site, depending on pipe size and hydraulic conditions.
G The ring should not be near the pipe mouth draw-down.
G Install the ring flat (flush) against the inside wall of the pipe; otherwise it
will obstruct flow and catch debris. Feel around the front and back edges of
the ring with your fingers, pushing and pulling on the edges of the ring until
you are sure that the ring is flat against the side of the pipe. This may take
several attempts as you tighten and loosen the spreader mechanism crank
before you are finished.
l Position the sensors in the pipe.
G Place the ultrasonic range sensor at the highest point in the pipe.
G Allow for some ring rotation because the ring will move slightly when the
spreader mechanism is used to fit the ring into the pipe. The ultrasonic
range sensor must be on the crown of the pipe.
G If a velocity sensor is used, place it directly below the ultrasonic sensor,
often at the bottom center of the pipe unless silt is present. If silt is present,
the sensor must be rotated to the left or right of the center until the sensor is
above the silt level.
G If a pressure depth sensor is used, place it in the flow and oriented to the
left or right of the velocity sensor, usually about 5 cm (2 in.). Verify that its
nose touches the bottom of the pipe to prevent debris from collecting on the
sensor and blocking its port. If silt is present, the sensor must be rotated
again to the left or right of the velocity sensor
l Use a carpenter’s level on the face of the ultrasonic range sensor, and verify
that the sensor's face is both horizontally and vertically level to the flow. Once
leveled, tighten the ring by turning the crank on the spreader mechanism in a
counter-clockwise direction until the ring is snug. Be careful not to tighten the
crank too much to prevent the crank assembly from bending. Once the ring is
snug, push and pull on the top of the ring to make sure the ring doesn’t move.
l Verify that the ultrasonic range sensor is level. Also, verify that the sensors are
in their proper positions. If the ring is not placed properly, turn the crank in a
clockwise direction to free the ring and install it again.
l If silt was present, replace the silt to its natural level where the ring was
installed. Be aware of the location of the sensors.
l Remove all slack in the sensor cables and secure them with large cable ties. To
perform this task, attach the 8 mm (3/8 in.) plastic cable ties, with a molded
anchor bolt bracket, to the sensor cable. Be careful not to overtighten at this
point. Slide the semi-tight cable ties in position with the 6 mm (1/4 in.)
stainless steel anchor bolts. Attach and pull snug. Anchor bolts should be