ADS Environmental Services FlowShark QR 775002 A4 - Manual (Page 37)

Sensor Installation and Connection 3-3
Investigating Site Characteristics
Before beginning installation activities, conduct a thorough
investigation of hydraulic and site conditions.
Flow Hydraulics
The hydraulics of a site directly affect the monitor's ability to
accurately measure flow depth and velocity. The following
characteristics indicate when a site exhibits hydraulic conditions
favorable for effective flow monitoring activities:
 Smooth Flow with Central Peak Velocities The
potential site should exhibit minimal ripples or waves. Choppy
or foamy flow will adversely affect sensor accuracy. Bulging
pipe joints, upstream curves, or upstream merging of pipes can
contribute to choppy and off-center peak flows.
 Absence of Significant Silt Buildup at Pipe Bottom
Silt present at an otherwise favorable site must be accounted
for to obtain accurate flow measurements. Therefore, the field
crew must measure the silt depth with a ruler and record the
results in the Profile
® software.
 Evidence of Surcharging Debris present on ladder rungs
or joints in the manhole may indicate the site experiences
surcharging. If this occurs on a regular basis, consider finding
an alternate location for monitoring the flow.
 Relatively Quiet Pipe A monitoring point in a pipe
experiencing loud noises, such as active drop connections, can
adversely affect the accuracy of ultrasonic depth measurements.
 Flow Traveling at Least One Foot Per Second Slower
flows enable debris to settle in the pipe, limiting the accuracy
of flow measurements.