Abstract
A technique is considered and tested for quick measurement of DO concentration in a large water body where the concentration varies in time and space: Commercial DO meters for field measurements usually take tens seconds to output a value with enough accuracy at one measurement point because of their tardy response. However, when the response characteristics are expressed by some mathematical equation which relates the inputted (real) signal to the outputted signal, it is possible to deduce a spatial distribution of DO concentration from a continuously outputted signal obtained by moving the meter in a water, and then the time for measurement can be remarkably reduced. In this study, this idea is realized by assuming the characteristic equation as a first order differential equation. Field experiments show that the deduced DO profiles satisfactorily agree with the profiles obtained from the ordinary measurement.
