Commissioning, calibration, measuring
Calibration
Before using the DO-100 for the first time, fill electrolyte into the electrode and
calibrate the device. Proceed as follows.
- Fill electrolyte in the electrode (see section “Replacement of electrolyte and
electrode head”)
- Insert the electrode connecting plug into the opening „PROBE INPUT“ on
the top of the gauge and lock the connecting plug to the DO-100 with the
„LOCK-ON“ slide switch. The electrode is locked if the „LOCK-ON“ slide
switch is pushed to the right side as far as it will go (viewed from the front).
- Press the „POWER“ key to switch the DO-100 on.
- After a brief DO-100 initialisation phase, press the „mg/I/O
2
“ key to switch
to the „%O
2
“ measuring range. The display indicates „%O
2
“.
- Now press „ZERO“ once. The display indicates „0.0 %O
2
“. The measured
value (oxygen content of the air) is indicated after a short while.
- Wait approx. 5 min. until the measured value has stabilised and no longer
changes.
- Now press the „CAL“ key. The display indicates 20.8 or 20.9 %O
2
. This is
the typical oxygen content of the air and is therefore used as the constant
for calibration.
Note
Check that the measuring electrode is always locked. Calibration should
always be performed in a well aired room. Calibration must be performed
each time the diaphragm or the electrolyte is changed.
Measuring
After calibration the DO-100 is ready to be used for measurements.
- Connect the measuring electrode with the gauge as described under „Cal-
ibration“.
- Press the „POWER“ key to switch the DO-100 on.
- The display indicates the measuring range „mg/l“. Should the display indi-
cate the measuring range „%O
2
“, press the „mg/l/O
2
“ once.
- Immerse the measuring electrode in the liquid to be measured up to the con-
ically expanding handle (approx. 45 mm) and stir so as to free the air bubbles
in the electrode. Once the display has stabilised, you can read off the value
for the dissolved oxygen in the liquid directly.
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