evacuated aneroid element
1aneroid — A thin, disc shaped box or capsule, usually metallic, partially evacuated of air and sealed, which expands and contracts with changes in atmospheric or gaseous pressure. The aneroid is the sensing and actuating element in various meters or gages …
2Barometer — Schematic drawing of a simple mercury barometer with vertical mercury column and reservoir at base …
3atmospheric pressure — Meteorol. 1. the pressure exerted by the earth s atmosphere at any given point, being the product of the mass of the atmospheric column of the unit area above the given point and of the gravitational acceleration at the given point. 2. a value of …
