ADS Environmental Services FlowAlert QR 775011 A2 - Manual (Page 64)

Pressure Depth Sensor and Float Switch Installation 3-41
Float switch suspended in manhole in relation to rungs and monitor
6. (applicable only for an additional float switch) Mount the
second float switch so that is secured at least 12 inches away
from the first float switch and adequately away from other
potential obstructions. Projects incorporating a second float
switch typically involve suspending the float switch at a
different elevation than the first float switch.