Principles of Dye Dilution

Dye dilution is a generic term that is based on the principles of fluorimetry. The combination of a fluorometer and fluorescent dyes forms a tracer system that is the basis of dye dilution investigations. Dye dilution methods involve the injection of a fluorescent dye tracer (typically Rhodamine WT) into a receiving body of water and measurement of fluorescence at a location further downstream. Flow rate at the downstream station can be determined by a mass balance which reduces to the ratio of concentrations of the injected and recovered tracer multiplied by the injection rate. Dye dilution flow rate measurements are typically accurate to ± 2%. Our proven procedures use a modified version of the ISO standard 9555-1:1994

Typical Dye Dilution Applications
 

• Calibrate flow meters, weirs and flumes in-situ.

• Develop rating curves for natural streams.

• Determine the efficiency of inverted siphons.

• Measure stream and conduit flow.

• Lift station / pump curve calibration.

• Hydraulic turbine performance testing.

• Determine inflow and infiltration.

• Determine actual residence times in sedimentation and chlorine contact tanks.

• Determine effluent outfall plume propagation.

• Services We offer.

Our staff have over fifteen years of dye dilution, flow meter installation, calibration and maintenance experience. We offer expert technical assistance in:

• In-situ flow meter calibration/verification by dye dilution or other techniques.

• Training programs and consulting on dye dilution and flow monitoring techniques.

• Flow meter audits - meter type, age, location, suitability for calibration, data management.

• Calibration of secondary instrumentation.

• Development of a meter calibration and replacement strategy.