A method for calibrating, auditing and controlling a liquid dispensing system, comprising: taking a portable device in hand having a flow meter (42; 43) and a hand-held controller, the flow meter (42; 43) being operably connected to the hand-held controller; removably connecting an inlet (38; 39) of the flow meter (42; 43) in-line with a liquid input to the dispensing system; operating the dispensing system; and acquiring liquid flow information from the flow meter for the liquid input; wherein the portable device comprises a first and second flow meter (42, 43) and the step of removably connecting: a. the inlet (38; 39) of the first flow meter (42; 43) to a liquid product input; and b. the inlet (38; 39) of the second flow meter (42; 43) to a liquid diluent input; wherein the inlet of the first flow meter has a quick-connector adapted for connecting the inlet of the first flow meter in-line to a first liquid input of the liquid dispensing system; and the inlet of the second flow meter has a quick-connector adapted for connecting the inlet of the second flow meter in-line to a second liquid input of the liquid dispensing system; further comprising the step of calculating a dilution rate using liquid flow information from first and second flow meters (42, 43), and the step of calibrating the liquid dispensing system based upon the measured liquid flow information. taking a portable device in hand having a flow meter (42; 43) and a hand-held controller, the flow meter (42; 43) being operably connected to the hand-held controller; removably connecting an inlet (38; 39) of the flow meter (42; 43) in-line with a liquid input to the dispensing system; operating the dispensing system; and acquiring liquid flow information from the flow meter for the liquid input; wherein the portable device comprises a first and second flow meter (42, 43) and the step of removably connecting: a. the inlet (38; 39) of the first flow meter (42; 43) to a liquid product input; and b. the inlet (38; 39) of the second flow meter (42; 43) to a liquid diluent input; a. the inlet (38; 39) of the first flow meter (42; 43) to a liquid product input; and b. the inlet (38; 39) of the second flow meter (42; 43) to a liquid diluent input; wherein the inlet of the first flow meter has a quick-connector adapted for connecting the inlet of the first flow meter in-line to a first liquid input of the liquid dispensing system; and the inlet of the second flow meter has a quick-connector adapted for connecting the inlet of the second flow meter in-line to a second liquid input of the liquid dispensing system; the inlet of the first flow meter has a quick-connector adapted for connecting the inlet of the first flow meter in-line to a first liquid input of the liquid dispensing system; and the inlet of the second flow meter has a quick-connector adapted for connecting the inlet of the second flow meter in-line to a second liquid input of the liquid dispensing system; further comprising the step of calculating a dilution rate using liquid flow information from first and second flow meters (42, 43), and the step of calibrating the liquid dispensing system based upon the measured liquid flow information. the step of calculating a dilution rate using liquid flow information from first and second flow meters (42, 43), and the step of calibrating the liquid dispensing system based upon the measured liquid flow information.