qMercury Barometers
–Height of mercury indicates downward force of air pressure
–Three barometric corrections must be made to ensure homogeneity of pressure readings
–First corrects for elevation, the second for air temperature (affects density of mercury), and the third involves a slight correction for gravity with latitude
qAneroid Barometers
–Use a collapsible chamber which compresses proportionally to air pressure
–Requires only an initial adjustment for elevation