Which device is used to measure runway friction in testing?

Which device is used to measure runway friction in testing?

• A. Pitot tube
• B. Mu-meter
• C. Anemometer
• D. Calibrated wheel

Answer: (B)

Measuring runway friction is about determining how well tires grip the surface, expressed as a friction coefficient μ. The mu-meter is designed for this task: it drags a wheel with a known load across the runway and measures the resisting force, from which μ is computed. This gives the friction reading that indicates braking effectiveness and surface condition. A pitot tube measures dynamic pressure to determine airspeed, not friction. An anemometer measures wind speed. A calibrated wheel isn’t the standard friction measurement instrument, though wheels may appear in other tests. So the mu-meter is the device used to measure runway friction in testing.

Measuring runway friction is about determining how well tires grip the surface, expressed as a friction coefficient μ. The mu-meter is designed for this task: it drags a wheel with a known load across the runway and measures the resisting force, from which μ is computed. This gives the friction reading that indicates braking effectiveness and surface condition. A pitot tube measures dynamic pressure to determine airspeed, not friction. An anemometer measures wind speed. A calibrated wheel isn’t the standard friction measurement instrument, though wheels may appear in other tests. So the mu-meter is the device used to measure runway friction in testing.