Working Principle – Nutating Disk Meter

A disc attached to a sphere is mounted inside a spherical chamber. As fluid flows through the chamber, the disc and sphere unit nutates. The

nutation causes a pin, mounted on the sphere perpendicular to the disc, to rock. Each revolution of the pin indicates a fixed volume of liquid has

passed. A mechanical or electromagnetic sensor detects the rocking of the

pin.

Diagrams

How it works

Volume flow rate

Liquid enters a precision-machined measuring chamber containing a disc which nutates (wobbles). The measuring chamber contains an exact

known quantity of fluid. Fluid pressure causes the disc to nutate and the

control roller causes the nutating disc to make a complete cycle. The measuring chamber is filled and emptied each cycle. The nutations of the

disc are transmitted by a gear train to a totalizer or pulse transmitter.

Characteristics

The nutating disc meter below is manufactured to handle hot water up to

250°F. It has a liquid-crystal polymer disc and a bronze housing. Disc meters made with aluminum or bronze discs are commonly used to meter

hot oil and chemicals.

Limitation

Accuracy is adversely affected by viscosities below the meter's designated threshold.

Advantages

High accuracy and repeatability. Handles thin liquids at relatively higher pressures

Compensates for wear through vane extension Sometimes preferred for solvents, LPG

Can run dry for short periods Can have one seal or stuffing box

Develops good vacuum Application

A fuel dispenser