Nested Parshall Flumes factory integrated into a Fiberglass Flow Metering Manhole.  Factory integration means that the flumes are installed correctly and the unit ships as a single piece - minimizing line downtime.  

Nesting of flumes involves installing a smaller, usually temporary, flume in a larger flume. This allows the operator to measure smaller initial flows and later, as flows increase, remove the smaller flume and measure the flow with the larger outer flume.