© PCE Instruments
5
Now press the HOLD key so that the display shows Hold. Then press the REC key. CAL will
flash in the display and a countdown will start counting down from 30.
As soon as the countdown is finished, the oxygen meter returns to normal measuring mode and
the calibration is finished.
The oxygen meter should now display a measured value between 20.8 ... 20.9 % O2 in fresh
air.
Hint
: Calibration works best when performed outdoors and in fresh air. If this is not
possible, the meter can also be calibrated in a very well ventilated room.
3.2
Measurement of dissolved oxygen in liquids
After the calibration has been carried out as described in chapter 3.1, the oxygen meter can be
used to measure dissolved oxygen in liquids.
Press the UNIT key for three seconds to change the unit from %O2 to mg/l. Now place the sensor
head in the liquid to be measured and carefully move the meter (sensor head) slightly back and
forth within the liquid. The measurement result can be read from the display after a few minutes.
Hint
: In order to obtain a quick and exact measuring result, the meter must be moved
within the liquid at a speed of approx. 0.2 ... 0.3 m/s. In laboratory tests, it is recommended to stir
the liquid in a beaker with a magnetic stirrer (e. g. PCE-MSR 350).
After the measurement is completed, the electrode can be rinsed with tap water and the protective
cap can be placed on the sensor.
