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Relative Pressure Calibration
In the calibration mode, press the
SET
key again, the “REL”
symbol will display at the pressure section, the relative
pressure value will flash. (The default value is 0.00 inHg)
Press the
C
key or
MAX/MIN/-
key to increase or
decrease the relative pressure value (in increments of 0.01
inHg).
Press and hold the
C
or
MAX/MIN/-
key for three
seconds to increase or decrease rapidly.
Press the
ALARM
key to reset current value.
Example
: The calibrated pressure sources measure 25.00
inHg. The display console pressure reads 24.85 inHg.
Offset = 25.00 - 24.85 = 0.15 inHg
Note:
The display console displays two different pressures:
absolute (measured) and relative (corrected to sea-level).
To compare pressure conditions from one location to another,
meteorologists correct the pressure to sea-level conditions.
Because the air pressure decreases as you rise in altitude, the
sea-level corrected pressure (the pressure your location would
be at if located at sea-level) is generally higher than your
measured pressure.
Thus, your absolute pressure may read 28.62 inHg (969 mb) at
an altitude of 1000 feet (305 m), but the relative pressure is
30.00 inHg (1016 mb).
