A Tracom fiberglass Parshall flume with end adapters mounted in a concerete manhole.  The flume was provided with what appears to have been a stainless steel (304 by the looks of the corrosion) bubbler tube.  Over the flume is mounted an ultrasonic sensor.

The flume is used to measure discharge out of a laundry facility as evidenced by the steam in the picture.  Typically ultrasonic meters are a poor choice in these applications due to the buildup of condensation on the underside of the ultrasonic transducer.