To ensure proper alignment of a wind vane, what instrument is used?

To ensure proper alignment of a wind vane, what instrument is used?

• A. Thermometer
• B. Barometer
• C. Compass
• D. Anemometer

Answer: (C)

A wind vane must be aligned with a known directional reference, since it indicates wind direction. A compass provides that reference by showing which way is north (and thus the other directions). By using a compass, you can orient the vane along a true north–south line (or adjust for magnetic declination if precision is needed) so the readings of wind direction are accurate. The other tools measure different things: a thermometer for temperature, a barometer for atmospheric pressure, and an anemometer for wind speed, none of which give directional orientation for aligning the vane.

A wind vane must be aligned with a known directional reference, since it indicates wind direction. A compass provides that reference by showing which way is north (and thus the other directions). By using a compass, you can orient the vane along a true north–south line (or adjust for magnetic declination if precision is needed) so the readings of wind direction are accurate. The other tools measure different things: a thermometer for temperature, a barometer for atmospheric pressure, and an anemometer for wind speed, none of which give directional orientation for aligning the vane.