What instrumentation do you use to measure bypass volume in a wastewater system?
asked 21 February 2016 asked by EtLeMondeSeraMeilleur (780 points)
Hello there, if the network (and budget) allows for it, the most reliable measure is an electromagnetic flow meter for partially filled pipes, like a Krohne Tidalflux. (Requires minimum height at 10% of diameter). Otherwise a level-velocity sensor works fine for laminar flow even after extended dry periods.
Hi, I have had good results with a piezo for bypasses. Monthly readings. Low zero drift. But why not use an ultrasound or radar? Unless you have foam, they're very reliable.
Hi, What kind of sensor do you use? I have had very poor results with NIVUS and Hydreka sensors. Velocity measurement is accurate, but there's a random offset in level measurement even with clean probes. thanks
Hi, Personally, I am using an ultrasound sensor on the main pipe with flow calibrated on discharge threshold. In another installation: surface laser, still on main pipe, with one test point upstream of discharge and one downstream (difference = volume discharged). Ijinus or Lacroix sofrel equipment currently 3 weirs are equipped > 600 kg of BOD and 15 more being estimated the complicated part is devising the formula to calculate past flow