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elevation the typical atmospheric pressure is about 900 mbar
compared to 1013 mbar at sea level).
Thus in summary, there are three important parameters to be
known for the air calibration standard:
Temperature (°C)
Relative Humidity (%RH)
Atmospheric Pressure (mbar)
The
FireSting
device and the
Pyro Oxygen Logger
software will
guide the user through all calibration steps, not requiring the
theoretical knowledge given above. And in case of a second
generation
FireStingO2
(with micro USB connector), the built-in
humidity and pressure sensors together with the internal or
external temperature sensor will measure these parameters
automatically for most calibration types (see also chapter 7).
8.1.1
Ambient Air
If ambient air is used as the air calibration standard, there is no
need for preparation. The
dry
oxygen sensor, optionally together
with the
dry
external temperature sensor, is simply exposed to the
ambient air. Otherwise, follow the calibration procedures given in
chapter 7.
For precise calibrations in ambient air, it is important that the
measuring tips of the oxygen and the temperature sensor are
completely dry
. Wet sensor tips will cause undefined humidity
levels around the sensor tips. And even worse, the evaporation of
water drops would cool down the sensor tips causing undefined
temperatures.
