Theory 74/Measurement & modelling/Tracer tests
Residence Time Is Injection Against Detection
The claim
The measurable residence time in a tracer test is set by the ratio of injected mass to detection limit, so a short test cannot resolve a long residence time.
01Mechanism
Concentration decays as the tracer disperses; the ratio determines how long it stays above detection.
02Prediction
Resolvable time should track the ratio.
03Refutation
Resolvable time tracking test duration would remove mass.