Question

Barometer which is calibrated directly to read the atmospheric pressure is

• A. Aneroid barometer
• B. Fortin's barometer
• C. Simple barometer
• D. None

Answer 1

The correct option is A Aneroid barometer

The Aneroid barometer uses a small, flexible metal box called an aneroid cell (capsule). The evacuated capsule (or usually several capsules, stacked to add up their movements) is prevented from collapsing by a strong spring. Since the instrument calibrated directly to read the atmospheric pressure, small changes in external air pressure cause the cell to expand or contract. This expansion and contraction drives mechanical levers such that the tiny movements of the capsule are amplified and displayed on the face of the aneroid barometer.