ADS Environmental Services FlowAlert QR 775011 A2 - Manual (Page 24)

3-1
C H A P T E R 3
Pressure Depth Sensor and Float
Switch Installation
The ADS ® FlowAlert

monitor, pressure depth sensor, and float
switch are primarily designed for monitoring flow in sanitary,
combined, storm sewers, and pump station wet wells. The monitor
mounts to the manhole rim or wall slightly below the manhole
cover.
The pressure depth sensor can mount to a stainless steel, expandable
ring or a stainless steel band installed in the sewer pipe a short
distance upstream from the manhole invert. A sewer system’s
hydraulics are much more stable and uniform in the incoming pipe
than in the manhole invert or outgoing pipe. Installing the sensor
upstream minimizes the hydraulic effects and erroneous data
readings caused by conditions in the pipe and the manhole.
The pressure depth sensor also can mount to a short, stainless steel
strap secured to the wall of the manhole or wet well when flow
depth measurements in the pipe are not applicable or necessary.
The float switch hangs from its cable in the center of the manhole,
and the cable is secured just below the manhole rim. Hanging the
float in the center prevents it from contacting or becoming tangled
with other objects in the manhole that may keep it from pivoting
properly when the flow rises or recedes.