Performance Of 1-Point Calibration; Performing 2- Or 3-Point Calibration - Tintometer Lovibond SD 315 Oxi Mode D'emploi

5.2.1 Performance of 1-point calibration

With 1-point calibration, the sensor is calibrated to the oxygen content of the air (20.95%).
There are basically two calibration options, and the sensor must be prepared accordingly.
1) Air calibration for highly accurate measurements in water-saturated air (Cal Air)
-> Recommended according to DIN EN ISO 5814:2013-02
With this type of calibration, the sensor is exposed to a relative ambient humidity of 100%.
The best way to do this is as follows:
cal
2) Calibration in air-saturated water (Cal AqUA)
This type of calibration is more difficult than 1) and can quickly lead to calibration errors if
insufficient care is taken, since water can easily become oversaturated. To produce air-saturated
water, pure water at room temperature is poured from one vessel into another from a height of
50 cm around 20 times. To avoid oversaturation, wait for about 5 minutes. Then immerse the
electrode in the air-saturated water and start calibration as described in 1), stirring all the time

5.2.2 Performing 2- or 3-point calibration

The sensor is automatically calibrated to the atmospheric O
and 1 or 2 additional concentrations. Calibration can then be carried out either on gases
(CAL = Air: air, pure oxygen [100%] or pure nitrogen [0%], or in correspondingly conditioned
liquids (CAL = AqUA). To do this, the liquids must be treated for a sufficient length of time
with the relevant gases..
48
Dampen the sponge in the supplied calibration
flask with distilled water. Transfer the sensor to
the calibration flask without touching the damp
sponge. The membrane must not become wet.
Allow the sensor to sit in the water-saturated air
for 15 minutes:
15 min
Start calibration by pressing the <CAL> button for
3 seconds. "Air Pt 1" now appears on the display.
Once calibration is finished, the current elec-
trode state is displayed as X% (X = 0 to 100).
Note: A correctly calibrated sensor shows an
O saturation of 102% O
2
temperature.
in air and at room
2
concentration in the air (20.95%)
2
SD_315_DO_1 06/2020