Method of compensating for changes in the flow characteristic of a fluid being dispensed from a nozzle

摘要

The invention relates to a method of compensating for changes in the flow characteristics of a fluid being dispensed from a nozzle (29) under the control of a metering valve (26) in order to maintain the volume of fluid dispensed over a predetermined interval at a desired setpoint. The method comprises the steps of: measuring the volume of fluid delivered to said metering valve (26) during at least one said interval; calculating a flow correction factor correlated to the difference between said measured volume and said setpoint; and multiplying the setpoint by said flow correction factor to yield a compensated setpoint.