Dye tracing
(重定向自Tracer dye)

Dye tracing is tracking and tracing various flows using dye added to the liquid in question. That is, it uses dye as a flow tracer. The purpose of tracking may be an analysis of the flow itself, of the transport of something by the flow of the objects that convey the flow. It is an evolution of the ages-known float tracing method, which basically consists of throwing a buoyant object into a waterflow to see where it goes or where it emerges..