A flow meter that must be installed vertically in a hydraulic system is the

A flow meter that must be installed vertically in a hydraulic system is the

• A. Rotameter
• B. Turbine Meter
• C. Piston Meter
• D. Vane Meter

Answer: (A)

Rotameters are variable-area flowmeters that use a float inside a tapered tube. The flow pushes the float upward until gravity and buoyancy balance with the flow, so the float settles at a height that directly indicates the flow rate. This setup requires the tube to be vertical so the float can move freely upward with increasing flow and stay stable for a readable measurement. If the meter is not vertical, the float won’t settle correctly and readings become unreliable. The other meters use different measurement principles—turbine meters rely on rotor speed, piston meters on displacement, and vane meters on a rotating vane—none of which require a strictly vertical installation, so they don’t fit the stated requirement.

Rotameters are variable-area flowmeters that use a float inside a tapered tube. The flow pushes the float upward until gravity and buoyancy balance with the flow, so the float settles at a height that directly indicates the flow rate. This setup requires the tube to be vertical so the float can move freely upward with increasing flow and stay stable for a readable measurement. If the meter is not vertical, the float won’t settle correctly and readings become unreliable.

The other meters use different measurement principles—turbine meters rely on rotor speed, piston meters on displacement, and vane meters on a rotating vane—none of which require a strictly vertical installation, so they don’t fit the stated requirement.