30
CALIBRA
TION
Single Point Manual Calibration
Determine the dissolved oxygen value of the sample using a reference method such as the Winkler
titration.
Place the
HI764113
probe in a sample, lake, basin, stream etc. that a recent dissolved oxygen
determination has been made. The probe should be at thermal equilibrium with the sample.
Press
CAL
. The calibration menu will be displayed.
Press
DO
to select the DO calibration.
Press the
Manual
functional key.
Using the / keys, adjust the standard value to the value determined previously.
When the reading is stable, the
CFM
functional key is displayed.
Press
CFM
to confirm the calibration point. The meter will return to the measurement screen and the
probe will store the calibration data.
9.2. PRESSURE CALIBRATION
The
HI98198
meter incorporates a pressure transducer that accurately tracks local barometric
pressure. Oxygen partial pressure is influenced by the local barometric pressure as dictated by Henry’s
Law. The
HI98198
automatically compensates dissolved oxygen measurements for these changes.
The
HI98198
’s pressure transducer is factory calibrated and no user calibration should be necessary.
If the pressure reading appears out of tolerance, the pressure reading can be checked and a calibration
performed if required. To calibrate pressure follow the instructions below. A reference barometer with
at least 1 mmHg resolution is required.