Cumulative Exit-Age Distribution Function, F t

The cumulative exit-age distribution function, F i), is defined as the fraction of fluid in the effluentfrom the vessel that was in the vessel for a time less than t. Said differently, F f) is the fraction of fluid leaving the vessel that has an exit age less than t. 

Calculation of cumulative exit-age distribution function from response to step input of tracer 

In Eqn. (10-5), C(t) is the concentration of tracer in the effluent stream after a sharp step change in the inlet tracer concentration from 0 to Cq at t = 0. 

---