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 mixing and dispersion of pollutants in rivers from outboard motors and in a gross pollutant trap (GPT). 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 is determined by injecting methylene blue dye over a range of water flow velocities. Despite some noise and drift, the data collected from the probe is useful because of its high frequency response in comparison to regular commercial concentration probes. The rise and fall times are reported and the theoretical response time is also determined. It is found that the frequency response is a strong function of flow velocity and a maximum of 100 Hz is noted under typical operating conditions. Comparison between rise and fall data show that the rise time is generally shorter than half the fall time.