Replenishment is used in photographic film and paper processing, where fresh chemistry is used to replace exhausted chemistry in a continuous or per-batch fashion. Replenishment rates are calculated by the quantity of film processed in each individual bath; and additionally in Process E6 by the amount of film push-processed; and by film type in Process C41 (color negative) developing.
Process C-41 and C41-RA replenishing
C-41 color developer exhaustion volumes vary according to the speed and contrast of the films. Please see Table 3-2 in chapter 3 of the Kodak Process C-41 Processing Manual Z-131 to see the different color developer exhaustion rates for the various Kodak color negative films. rate at which stock is added
References
Replenishment (photography) Wikipedia(Text) CC BY-SA