Reduction of sampling time in tracer studies

An approach of evaluation of dispersion number has been suggested. Unlike the existing method, which is based on fixed-point continuous monitoring until the tracer concentration has been reduced to negligible concentration, the new approach assumes that sampling takes place at various equidistant points along the pond or channel simultaneously or at variable times. The new approach was illustrated with laboratory data and gave results 0.9–3.3 higher than those obtained with the conventional Levenspiel and Smith fixed-point continuous-monitoring method. Its advantages over the existing methods, which include savings in time, economy, convenience, and flexibility, were also discussed. The Levenspiel and Smith method was employed in analysis and comparison.