Paddlewheel flowmeters can be used to start and stop inexpensive, motor-driven fixed feed rate metering pumps without the need for expensive PLCs or other control equipment. When the meter has determined that a preprogrammed volume of flow has passed through the system, control circuitry in the meter turns on the chemical pump for a preprogrammed amount of time, usually a few seconds, and then back off again. Although this method results in an uneven “pulsed” dispersion of chemical in the system, it is simple to install and results in a highly accurate, easy-to-maintain proportional feed system.
