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SDL150-EU-EN-V2.1-11/11
Calibration
20.9% Oxygen in Air Calibration
1. Connect the DO probe to the input jack at the top of the meter
2. Power the meter by pressing and holding the power button for 1.5 seconds
3. Press and hold the FUNCTION button for 1.5 seconds to switch from mg/L mode to O2 mode
4. Allow the probe to stabilize for at least 5 minutes in a large well ventilated environment.
5. Press and hold the CAL button for 1.5 seconds. The CAL icon will appear
6. Momentarily press the ENTER button while the CAL icon is displayed. The display will indicate a
countdown from 30 to zero. Note that if the ENTER button is not pressed while the CAL icon is
being displayed, the calibration procedure must be attempted again
7. When the countdown finishes the calibration is complete
8. If the calibration is unstable, check the electrolyte level and/or replace the probe head (includes
diaphragm)
Zero Calibration
The 0% calibration is available for high accuracy measurements at low O
2
levels. The calibration
requires a Zero Oxygen Solution which can be purchased from most laboratory supply distributors.
This calibration is not required for typical O
2
measurements.
1.
Power the meter on and set it to DO mode (you should see mg/L in the top right of display).
2.
Immerse the probe in 4” of zero oxygen solution; agitate or slowly stir the probe in the solution
to remove any air bubbles and allow the reading to stabilize.
3.
Once the reading has stabilized, press and hold the UP and DOWN arrow buttons until CAL 0
appears in the lower portion of the display.
4.
Release the UP and DOWN arrow buttons; calibration is complete.
