Glossary Of Common Terms - Fine offset HP2550 Operation Manual

11. Glossary of Common Terms

TERM
ABSOLUTE AIR PRESSURE
ABSOLUTE BAROMETRIC
PRESSURE
BAROMETER
BEAUFORT (Bft)
DEW POINT
HEAT INDEX
HECTOPASCALS (hPa)
HYGROMETER
DESCRIPTION
Absolute air pressure is the air pressure
registered on a barometer without regard to
altitude.
A barometer is a device that measures the
pressure of the air pushing on it—this
measurement is called the barometric
pressure. We don't actually feel the
barometric pressure because the air pressure
is pushing equally in every direction.
An indicator of wind force strength (not
speed) as it would act on a ship's sails. Still
commonly in used in some locales to
indicate wind force.
The temperature to which air must be cooled
to become saturated with water vapor. When
further cooled, the airborne water vapor will
condense to form liquid water (dew), or frost
if below freezing.
The heat index (HI) or humiture is an index
that combines air temperature and relative
humidity, in shaded areas, as an attempt to
determine the human-perceived equivalent
temperature, as how hot it would feel if the
humidity were some other value in the shade.
This is an international standard (SI system)
for measuring air pressure. It used to be
referred to as milli-bar (mb) and sometimes
still is. They are equivalent.
An instrument
humidity of the air. This is expressed as a
79
that measure relative