H Flumes:
From torrents to trickles, the H Flumes can accurately measure flows that vary widely. The flumes fall into three series (H, HS, HL) as shown in the capacity table. The flume size is equivalent to the height of the flume at the inlet end. The approach channel is rectangular in cross section, with the same width and height as the flume entrance. The recommended length of the approach channel is three to five times the flume size. The flume must be installed level. The approach channel may have a slope of 2° or less, and the flow must be tranquil and sub-critical. As the flow exits the flume, it must spill clear so that there is no submergence (backup in the flume).

Options: Approach channels Stilling wells Staff gauges Wide variety of instrument accessories

Trapezoidal Flumes:
Trapezoidal flumes were originally developed by the U.S. Soil Conservation Service to measure flows in irrigation channels. Trapezoidals are currently being widely used for sewer flow monitoring in applications with very low minimum flows. The lack of a raised still coupled with the high velocities in the throat enables these flumes to clear sediment effectively. The trapezoidal throat shape affords floating debris the opportunity to rise and pass through a more open cross-section.

Options:

• Stilling wells
• Staff gauges
• Wide variety of instrument accessories