Calculating Precipitation Rate
Custom nozzles use the precipitation rate (PR) which is a calculation of the flow rate (application rate) over the square footage of the zone.
Let's break down the equation for everyone to better understand:
PR = (96.25(A * B)) / (C)
96.25 = constant that converts gallons per minute (GPM) to inches per hour. It is derived from 60 minutes per hour divided by 7.48 gallons per cubic foot, times 12 inches per foot.
A = # of heads -or- # of emitters
B = flow rate (GPM) per head -or- emitter
C = zone square footage