Dissolved Oxygen (Do) Calibration With The Inlab® Optiox - Mettler Toledo SevenGo pro Instrucciones De Montaje

There is no automatic pH buffer recognition for customized buffer groups; in this case, the defined order of the
buffers needs to be followed.
4.8.4 Dissolved oxygen (DO) calibration with the InLab® OptiOx
Under equilibrium conditions, the partial pressure of oxygen in air-saturated water is equal to the partial
pressure of oxygen in water-saturated air. This means that an OptiOx sensor calibrated in water-saturated air
will correctly read the partial pressure of oxygen in water samples. When measuring low concentration
samples (less than 1 mg/L), a second calibration with a zero oxygen standard may be done.
Performing a one-point calibration
The first point of a DO calibration is always done in water-saturated air (100% O
1 Remove the OptiOx calibration tube cap and remove the sponge from the cap.
2 Saturate the sponge with distilled water and squeeze the excess water out of the sponge.
3 Reassemble the OptiOx calibration tube.
4 Make sure that no water droplets are on the surface of the OptiOx sensor cap.
5 Slide the calibration tube over the front of the sensor until the calibration tube is firmly connected to the
sensor.
6 Allow at least five minutes for the temperature to stabilize prior to calibration.
7 Press and hold MODE for 3 seconds to switch to single channel measurement screen when in dual
channel measurement (only SG98).
8 Press CAL.
Cal 1 appears on the display.
The meter endpoints according to the preselected endpoint mode, automatically after the signal has
stabilized or after pressing READ. The standard value is shown on the display.
9 Press End to accept the calibration and return to sample measurement.
The calibration result is shown on the display.
10 Press Exit to reject the calibration.
Note
Under equilibrium conditions, the partial pressure of oxygen in air-saturated water is equal to the partial
pressure of oxygen in water-saturated air.
Performing a two-point calibration
The second point of a DO calibration is done with a zero oxygen solution.
1 For the first calibration point follow the steps (a-h) as described above in "Performing a one-point
calibration".
2 Remove the calibration tube.
3 Rinse the sensor with deionized water.
4 Prepare a zero oxygen solution and place the InLab
5 Allow at least five minutes for the sensor to equilibrate prior to calibration.
6 Press CAL.
Cal 2 appears on the display.
The meter endpoints according to the preselected endpoint mode, automatically after the signal has
stabilized or after pressing READ. The relevant buffer/standard value is shown on the display.
7 Press End to accept the calibration and return to sample measurement.
The calibration result is shown on the display.
8 Press Exit to reject the calibration.
9 Thoroughly rinse the sensor under running water and blot it dry with a lint-free tissue
Note
Zero-point calibrations are frequently a source of error. Due to the very low zero current of
METTLER TOLEDO sensors, a zero-point calibration is unnecessary even for measurement at low oxygen
concentrations.
16 Operating the pH/ORP/Ion/DO meter SG98 and DO meter SG9​ ​
).
2
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OptiOx into the bottle.
SevenGo (Duo) pro™/OptiOx™