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.

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.

The ASFM Advantage provides the hydroelectric industry with a reliable, accurate and cost-effective method of measuring discharge, especially at low-head hydro plants with short or irregular intakes, where accurate discharge measurement has traditionally been difficult. If intake slots are available and the ASFM Advantage can be mounted on frames, overall measurement costs are significantly lower than with competitive technologies using dedicated (built-in) instruments. This is particularly significant at plants with multiple units