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due to the actual weather conditions. Therefore, determining the
actual atmospheric pressure with a barometer gives more precise
results.
The relative
Humidity
(%RH)
of the gas phase (e.g. air) needs to
be adjusted. If a calibration standard with water-vapor saturated
air is used (see chapter 8.1.2), it must be adjusted to 100%RH.
Otherwise, the humidity must be determined with a hygrometer
and entered. If the current
Humidity
cannot be determined, a
value of 40% is a good estimate (under normal conditions around
20°C, an incorrectly entered humidity will cause a max. calibration
error of ca. 1% deviation).
Place now the oxygen sensor and the external temperature sensor
(if used) into the air calibration standard.
NOTE
: If using retractable needle-type sensors (e.g.
OXR50
,
OXR230
,
OXR430
), it is important that the sensor tip is extended to
position 2 or 3 (see chapter 5.1) when the calibration value is taken.
Wait for steady state until the sensor reading is stable by observing
the graph. If
External Temperature Sensor
was selected, ensure
also stable temperature readings indicated at
Temperature
Sensor (°C)
. Note that the button
Set Air
will be highlighted as
soon as the oxygen readings are within the expected range for the
connected sensor type (the latter does not apply for a custom air
calibration with ≠20.95 %O2).
If all readings have reached their steady state, click on
Set Air
, and the actual oxygen sensor reading is taken
for the air calibration. If the oxygen reading seems to be
out of the expected range, a warning will be shown
offering the possibility to repeat the calibration. A
completed air calibration is indicated by the green
indicator
Calibrated at Air
.
