Assessment of a Scalar Concentration (Komori) Probe for Measuring Fluctuating Dye Concentration in Water

Abstract

The scalar (dye) concentration probe of Komori has been used at QUT to measure the dispersion of pollutants in rivers from outboard motors and the residence time distributions of stormwater quality improvement devices (SQIDs). Although usages have been documented in literature, little is known of the Komori (dye) probe’s frequency response characteristics and the quality of data sampled. In this work, the frequency response characteristic of the Komori probe was determined by injecting methylene blue dye upstream of the probe flume under varying flow conditions. Despite noise and drift, the data collected from the probe provided is useful because of its high frequency response in comparison to other types of tracer measurement. The rise and fall times were reported and the theoretical response time was also determined. It was found that the frequency response is a strong function of flow velocity and a maximum of 100 Hz under typical operating conditions is determined. Comparison between rise and fall data showed that fall curve takes longer time to dissipate.