Skip to main content


Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

A field verification of reference flow and water level meters was done as part of the Environmental Technology Verification (ETV) program of the U.S. Environmental Protection Agency (USEPA), under the “Wet-Weather Flow Technologies” pilot program managed by NSF International during the summer of 2001. One of the technologies verified under this pilot program is the “Flow Monitoring Equipment”, which requires the verification of reference meters under the terms of the Generic Protocol entitled “Verification of Flowmeters for Stormwater and CSO Applications in Mid-size Pipes”. A full description of the ETV program and a copy of the Generic Protocol can be consulted on the following web site:

This paper presents the testing site and the results of the field verification of the reference meters used to verify the vendors' flowmeters as part of the ETV program. The testing site is a section of the Quebec Urban Community's (QUC) interceptor network. The accuracy of three meters was verified: one four-path transit-time flowmeter and two level meters, a bubbler and an ultrasonic level meter. A total of nine active tests were performed: three tests B (dry-weather flow with and without backflow), C (wet-weather flow without backflow) and D (wet-weather flow with backflow and surcharge conditions). The verification of the accuracy was based on a comparison with a reference method. The concentrations of blank, concentrated and diluted samples obtained from the lithium dilution analyses were used to estimate flow rates. Manual level measurements were used to verify water levels.

The Field Testing Organization recognized that the four-path transit-time flowmeter and both the bubbler and ultrasonic level meters did not meet the accuracy requirements specified in the Generic Protocol in order to be validated as the reference meters. Nevertheless, in light of the results obtained using the revised flow accuracy margins and considering the unexpectedly low accuracy of the tracer dilution analysis results, as well as the good fit with the flow rates estimated with the “flow under the gate” equation, the four-path transit-time flowmeter was validated as the reference flowmeter to verify the vendors' flowmeters. Furthermore, in light of the fact that the performance results are affected by the presence of waves during the two highest flow rates of Test C and knowing that the bubbler level meter is less impacted by waves than are the manual measurements and ultrasonic readings, the bubbler level meter was validated as the primary reference level meter and the ultrasonic as the secondary (or redundant) level meter to verify the vendors' flowmeters.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Data/Media
No Metrics

Document Type: Research Article

Publication date: 2002-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more