Measuring bulk amounts of liquid can be a difficult task without the proper tools. Liquid flow meters are one of the most popular devices for measuring liquids in bulk. While several technologies exist, the positive displacement meter is the one most commonly used for utilities and inventory management industries such as molasses batching for animal feed production, gas station pumps, and water metering. What makes a positive displacement meter so effective? The answer is found in the nutating disc, a mechanism designed in the center of the meter.

Nutating discs are most often used in feed production, fuel metering, and water metering. This simple yet reliable component is crucial to the operation of positive displacement meters. Nutating discs measure fluids accurately by using the flow of the liquid.

Liquid enters the flow meter through a chamber. Once in the chamber, the liquid encounters a ball with a disc attached. The ball and disc combo are held together and in place by a shaft positioned by a cam or roller. As the liquid flows through the chamber the disc nutates, or wobbles, around an axis. The position of the disc divides the chamber into compartments containing an exact volume. Each fill and empty of the chamber (cycle) corresponds to a fixed amount of fluid. Movements are transmitted by a gear train to the register/totalizer or pulse transmitter. The precise fit of the disc inside the chamber ensures accurate and repeatable measurement of each volume cycle.