9
4. Calibration
Probe guard
Preparing the meter for calibration
Before calibrating your meter, make sure to rinse the
probe well with de-ionized water or rinse solution.
NOTE:
Do not let membrane surface of the probe
touch any other surface. The probe guard
(the piece with holes fitted over the end of
the probe) protects the membrane; make sure
this is always attached to the probe while it is
in use.
You can calibrate for dissolved oxygen in either
% saturation or mg/l (ppm). All new calibrations
automatically override existing calibration data.
Before calibration
Before starting calibration, make sure you are in the
correct measurement mode. When you switch on the
meter, the meter starts up in the units last used (either
mg/l, ppm, % air saturation, or clock). For example, if
you shut the meter off in “mg/l” units, the meter will
read “mg/l” units when you switch the meter on.
NOTE:
Most users will calibrate to 100% saturation
even when working in mg/l. When calibrat-
ing the meter in mg/l mode, you can make
fine adjustments, typically to a midrange
value between 10 and 100%. If you are
calibrating to a midrange value, you need
to set the 100% saturation value first.
4.1