Fluid Flow: As fuel or other compatible fluid flows through the meter, it enters a chamber containing a nutating disc.
Disc Nutation: The pressure of the flowing fluid causes the disc to "nutate" or oscillate in a precise, rocking motion.
Volume Measurement: Each complete nutation of the disc corresponds to a fixed, known volume of fluid.
Mechanical Registration: A mechanical mechanism detects and counts these nutations, translating them into a volume measurement displayed on the meter's register.
Display: The meter features both a resettable 4-digit counter for current batch volume and a non-resettable totalizer (often 7-digit) to track the total volume dispensed over the meter's lifetime.