Influencing Factors - Honeywell Envitec MySignO Operating Manual

Oxygen measuring device MySign
4.9.2

Influencing factors

The effects of gas pressure and measured gas humidity
The oxygen sensor measures the partial pressure of the oxygen in the gas mixture, but the
unit only shows the oxygen concentration and therefore needs to be calibrated.
When being calibrated, the partial pressure of the oxygen in dry ambient air is equated with a
concentration by volume of 20.9% O
oxygen) contained in the gas will vary slightly depending on the absolute humidity of the
measured gas. The effects of the humidity do not need to be taken into account since the error
for the entire operating temperature range between absolutely dry and saturated gas is less
than 1% O .
2
The unit should always be calibrated in the same pressure conditions in which
the measurements are performed so as to compensate for the potential effects
caused by pressure differences. The relevant pressure conditions during the
measurement are the gas mixture pressure or current air pressure, which takes
into account the elevation above sea level at the measuring location.
Ambient temperature
The measuring unit will compensate for any effects arising from changes in the ambient
temperature.
However, the measuring unit with the oxygen sensor must still be adapted to the ambient
temperature. Brief but significant gas temperature fluctuations can temporarily affect the
accuracy of the oxygen readings.
Water
The sensor and jack socket must never be fully wetted with water. Any water on the oxygen
sensor's gas inlet area will affect the measurement result.
If the unit becomes wet for any reason, its surface can be wiped dry with a cloth. In this case,
we advise waiting until the sensor has dried before switching the unit on.
30
®
O
. The percentage of oxygen (partial pressure of the
2
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