Parshall Flumes and ASTM D1941 & ISO 9826

When Dr. Parshall published his studies on what would come to be known as the Parshall flume he originally did so in The Colorado Agricultural College publication: The Improved Venturi Flume.

Over time the versatility of the Parshall flume saw it used in a number of diverse applications, including water rights apportionment, watershed monitoring, and sewage treatment plants. The growing acceptance of the flume also saw a number of investigation on the flow principles of the flume, its use, application, as well as extensions of the flume’s design for larger and smaller flow rates.

For many years the Bureau of Reclamation’s Water Measurement Manual, first published in 1953, and the USDA Circular No. 843, also published in 1953, served at the reference sources for Parshall flume dimensions, flow characteristics, and application.

Ultimately, a need was perceived for the standardization of the flume by the world’s technical standards organizations – ASTM and ISO. As a short-throated flume, it is important that the dimensions of the flume be exact (and standardized).

In 1991, ASTM standardized the Parshall flume in ASTM D1941-91 Standard Test Method for Open Channel Flow Measurement of Water with the Parshall Flume

ISO followed in 1992 with ISO 9826:1992 Measurement of Liquid Flow in Open Channels – Parshall and SANIIRI Flumes.

Over the intervening years, both the ASTM standard has seen several revisions, notably in 1196, 2001, 2007, and 2013. The ISO standard had not been updated since its publication in September of 1992.