ASL AQFlow Inc.’s Acoustic Scintillation Flow Meter (ASFM) is globally recognized as a solution to the hydroelectric industry’s toughest turbine flow measurement challenge – accurate and repeatable measurements in intakes of low-head power plants with no penstocks. The features of the method that make it a cost-effective solution for low-head plants apply equally to many higher-head plants as well.

The ASFM is a real-time, non-intrusive instrument that excels at performing:

flow measurement for turbine efficiency optimization
flow measurement before and after rehabilitation and
continuous monitoring of flow conditions.

In order to meet our client`s needs, AQFlow has developed two variations of the instrument, both installed in the intakes:

ASFM Advantage - a portable, frame-mounted instrument for short-term measurements without intake dewatering
ASFM Monitor - a permanently mounted instrument for reliable and repeatable long-term flow monitoring.

ASL Environmental Sciences Inc. (ASL), of which ASL AQFlow is a wholly-owned subsidiary, has been carrying out successful flow velocity measurement programs in difficult ocean environments from the Arctic to the tropics with acoustic scintillation methods since 1977. ASL has been working in hydroelectric applications for over 20 years, since October 2000 as the ASL AQFlow subsidiary.

Early measurements at low-head plants

A prototype of the Acoustic Scintillation Flow Meter (ASFM) was introduced at Rocky Reach dam, Chelan PUD, in 1992.

The first model of the ASFM was used for flow studies at Fort Patrick Henry and Wheeler Dams, Tennessee Valley Authority, in 1997 and 1999.

The first production ASFM system was produced for the US Army Corps of Engineers (USACE), Portland District in 1998. Between 1998 and 2001, measurements with this system were conducted successfully at McNary, Bonneville, Lower Granite and The Dalles Dams.

What the ASFM can do for you

ASFM Advantage: One-time measurements of absolute or relative turbine discharge to:

determine optimum settings for maximizing operating efficiency of individual units and/or entire plants,
facilitate field performance testing and/or acceptance testing,
check measurements obtained with other technologies,
calibrate Winter-Kennedy taps,
review effects of fish diversion screens on turbine efficiency.

ASFM Monitor: Continuous long-term flow measurement in near-real time to:

monitor unit/plant performance,
document compliance with regulatory/environmental requirements,
monitor trashrack blockage,
detect penstock rupture.

ASL Environmental Sciences Inc. (ASL), of which ASL AQFlow is a wholly-owned subsidiary, has been carrying out successful flow velocity measurement programs in difficult ocean environments from the Arctic to the tropics with acoustic scintillation methods since 1977. ASL has been working in hydroelectric applications for over 20 years, since October 2000 as the ASL AQFlow subsidiary.

Early measurements at low-head plants

A prototype of the Acoustic Scintillation Flow Meter (ASFM) was introduced at Rocky Reach dam, Chelan PUD, in 1992.

The first model of the ASFM was used for flow studies at Fort Patrick Henry and Wheeler Dams, Tennessee Valley Authority, in 1997 and 1999.

The first production ASFM system was produced for the US Army Corps of Engineers (USACE), Portland District in 1998. Between 1998 and 2001, measurements with this system were conducted successfully at McNary, Bonneville, Lower Granite and The Dalles Dams.

ASFM - Plant and System-Level Optimization Brochure