Instruction Manual
PD 300
4.5
Dissolved Oxygen Calibration in % Saturation
You can calibrate this meter quickly and easily in air. The exact calibration value depends on
barometric pressure. The meter is set to a factory default of 760 mm Hg, which results in a
calibration value of 100% saturation in air.
NOTE
If the barometric pressure setting has been changed from 760 mm Hg, the calibration value in
air will automatically adjust to a value other than 100%. The adjusted value will be correct for
the new barometric pressure setting.
See Section 8.6.1 on page 37 to change the pressure setting. See Addendum 2 on page 67
for a table of adjusted % saturation values.
To calibrate 100% Saturation:
1. Rinse the probe well with deionised rinse water. Do not touch
the membrane.
2. Press the MODE key to select the % saturation mode.
3. Press the CAL key. The CAL indicator will appear above the
primary display. The primary display shows the current value
of the measurement and the secondary display will show
100.0. See figure on right and NOTE above.
4. Hold the probe in the air. Wait for the reading to stabilise. If
the READY indicator feature is enabled, it will appear when
the reading is stable. (See page 45 for Ready indicator
setup.)
5. Press the ENTER key. The meter automatically calibrates to
100.0% air saturation and returns to Measurement mode.
NOTE
Whenever an error occurs during calibration, the ERR indicator
appears in the lower left hand corner of the display.
You can offset your % DO calibration. See page 40 for directions.
Figure 10: To calibrate for
100% saturation
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