This type of barometer is much more portable than
the mercury barometer and is found in many homes. It uses a partially evacuated metal box
with thin corrugated sides that is stopped from collapsing by a strong metal spring that is
fixed to one side. The box is connected to a dial by a set of levers and a light chain.
When the atmospheric pressure changes the box is stretched or squashed a little.
This movement is magnified by the system of levers and so the pointer moves.
An
Aneroid barometer can also be used as an altimeter in an aircraft because the pressure of
the atmosphere changes with height. The lower the pressure the higher the
plane.
