calibration feature allows you to zero out this error. To calibrate humidity, you will need an
accurate source, such as a sling psychrometer or Humidipaks One Step Calibration kit.
5.9.3 Setting Calibrated Barometric Pressure
In normal mode, press and hold the
SET
and
ALARM
keys at the same time for five seconds to
enter the barometric pressure calibration mode. The absolute relative pressure (ABS) will begin
flashing.
1.
Absolute Pressure.
Press the [+] or [-] key to increase or decrease the absolute pressure
reading (in increments of 0.01). Press and hold the [+] or [-] key for three seconds to increase
or decrease rapidly.
Press the
ALARM
key to reset current value.
Press the
SET
key to adjust the relative pressure.
2.
Relative Pressure.
Press the [+] or [-] key to increase or decrease the relative pressure
reading (in increments of 0.01). Press and hold the [+] or [-] key for three seconds to increase
or decrease rapidly.
Press the
ALARM
key to reset current value.
If no operation is performed, the calibration mode will timeout in 30 seconds.
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 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).
The standard sea-level pressure is 29.92 in Hg (1013.2hpa). This is the average sea-level pressure
around the world. Relative pressure measurements greater than 29.92 inHg (1013.2hpa) are
considered high pressure and relative pressure measurements less than 29.92 inHg are considered
low pressure.
To determine the relative pressure for your location, locate an official reporting station near you
(the internet is the best source for real time barometer conditions, such as Weather.com or
Wunderground.com), and set your weather station to match the official reporting station.
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