Recommended Practice for the Use of Parshall Flumes and Palmer-Bowlus Flumes in Wastewater Treatment Plants

摘要

Parshall and Palmer-Bowlus flumes are suitable for in-plant open channel flow measurement of raw wastewater and treated effluent as well as wastewater in intermediate stages of treatment. Parshall flumes are empirical devices which must be fabricated and installed according to specific requirements in order to yield the 'standard' values of discharge. The discharge of Palmer-Bowlus flumes can be determined analytically within specified error limits provided that described criteria for construction and installation are met. The accuracy of a flume-based measuring system depends upon a combination of the accuracies of the flume itself and the secondary instrumentation. The basic uncertainty of properly constructed and installed flumes is about + or - 3 percent. Suggested methods of calibrating and monitoring the performance of the flumes and secondary instruments are described.