On a turbine water meter, the volume reading is directly proportional to the revolutions of which component?

• A. The rotor
• B. The turbine blade
• C. The pump impeller
• D. The valve stem

Answer: (A)

In a turbine water meter, the flow turns a rotor. Each complete turn of that rotor moves a fixed amount of water, so counting rotor revolutions and multiplying by the volume per revolution gives the total volume. The meter’s register translates those turns into the volume shown. The other parts aren’t what the reading is based on: the impeller is for pumping, not measuring; the valve stem is a control component; and while the turbine blade is part of the rotor, the measurement is tied to the rotor’s revolutions as a whole.