H36.0.01.6C-13
Operating Manual GMH 3610
page 9 of 12
10.1 1-Point calibration
The 1-point calibration adjusts the electrode to the oxygen content of the atmosphere
(20.95%). Remove protective flask prior to calibration and wipe diaphragm with a soft piece
of cloth. You can choose between two modes of calibration for which the electrode has to
be prepared accordingly. We recommend to calibrate for each set of measuring.
Air calibration without accessories
The electrode will be exposed to
ambient air.
To protect it from
draughts, wrap electrode in a towel or Kleenex. (before calibra-
tion, expose electrode at least 15 minutes to the ambient air, to
let the temperature adjust and to dry membrane)
Depending on the rel. atmospheric humidity [%] and the tempera-
ture [°C] a small calibration error cannot be avoided and will have
to be accepted. The cooler the air the smaller the deviation. Rec-
ommended temperature < 25°C. For error compensation please
refer to the opposite table.
Note: A correctly calibrated electrode shows 106 - 108% at air
and at room temperature.
Air calibration for highly accurate measurements
The electrode is exposed to
air with a relative atmospheric humidity of 100%
.
Proceed as follows: Put some distilled water in a bottle. Close bottle and generate a water steam saturation (100%
rel. atmospheric humidity) in the remaining air by shaking it vigorously for approx. 3 minutes. Both water and air
temperatures should be identical. Open bottle and insert electrode so that the diaphragm is in the air chamber.
Attention
: By no means must the diaphragm get wet or be immersed in water. The bottle neck opening should only
be slightly larger than the electrode diameter; make sure to avoid over pressure in the container.
Note: A correctly calibrated electrode shows 106 - 108% at air and at room temperature.
Start calibration: press
-key for 2 sec.
The display will show 'CAL'; calibration will be automatically completed as soon as the measuring values for oxygen
and temperature are stable.
Then the electrode state resulting of the successful calibration will be shown for a short time (evaluation in 10%
steps).
In case of error messages being displayed during the calibration process, please refer to our notes at the
end of this manual! If a calibration cannot be carried out after an extended period of time, at least one of
the measuring values in unstable (oxygen partial pressure, temperature). Please check your measuring
arrangements!
10.2 Valuation of sensor state (ELEC)
Watch sensor state:
press key "CAL" shortly once
display show for a short time xx% ELEC
It will show the electrode state resulting of the last successful calibration carried out.
The valuation is displayed in 10 percent steps: 100% means optimal sensor condition. Lower values are indicating
that the sensor life time will be reached soon.
Remark: But also a erroneous pressure entry may be the cause of low valuation values.
20%
40%
60%
80%
100%
5 °C
1.007 1.005
1.003
1.002
1.00
10 °C
1.01
1.007
1.005
1.002
1.00
15 °C
1.014
1.01
1.007
1.003
1.00
20 °C
1.019
1.014
1.009
1.005
1.00
25 °C
1.026
1.019
1.013
1.006
1.00
30 °C
1.035
1.026
1.017
1.009
1.00
35 °C
1.047 1.035
1.023
1.012
1.00
40 °C
1.063 1.047
1.031
1.016
1.00
Deviations when carrying out an air calibration
without accessories,
O2-saturation= display value*corr. factor