ECOWITT WH2910, Operation Manual

Page: 62 / 67

62
10 Glossary of Common Terms
TERM DESCRIPTION
ABSOLUTE AIR
PRESSURE
ABSOLUTE
BAROMETRIC
PRESSURE
Absolute air pressure is the air pressure registered on
a barometer without regard to altitude.
BAROMETER
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.
BEAUFORT (Bft)
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.
DEW POINT
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.
HEAT INDEX
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.
HECTOPASCALS
(hPa)
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.
HYGROMETER
An instrument that measure relative humidity of the
air. This is expressed as a percentage between 0%
and 100%.