Calibration Of The Oxygen Electrode; Performance Of 1-Point Calibration; Do Measurement - Lovibond SD 335 Multi Manual Del Usuario

6.2 Calibration of the oxygen electrode

Due to the ageing of the sensor, the oxygen sensor must be calibrated regularly.
To do this, the device features easy-to-use calibration functions. We recommend
carrying out calibration every seven days or so, or immediately before measure-
ment in order to ensure the greatest possible measuring accuracy. Please set the
USB mode to mass storage in the instrument configuration before calibration.

6.2.1 Performance of 1-point calibration

With 1-point calibration, the sensor is calibrated to the oxygen content of the air (20.95%).
 Recommended according to DIN EN ISO 5814:2013-02
In this type of calibration, the sensor is exposed to water-saturated air (100% humidity).
Proceed as follows:
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 before
calibration.
15 min
Select the parameter O
can now be started by pressing and holding the F1 key.
When the calibration is finished, the sensor status is evaluated
and indicated in %.
The O
now be around 102 %.

6.3 DO measurement

Before each measurement, check whether a salinity correction is necessary, since the content
of dissolved oxygen in an aqueous sample is strongly dependent on the salt content. When
measuring dissolved oxygen, the following procedure must be observed:
Remove stor- Rinse electrode
age bottle with distilled
water
SD_335_1 10/2020
in operation mode. The calibration mode
2
saturation in the calibration bottle (water-saturated air) should
2
Note immersion
depth of at
least 3 cm
T
3 cm
T
Sample
Adjust the
temperature of
the sensor (T
Elec
and sample
(T )
Sample
°
Elec 90
=
Hold the sensor
as vertically
) as possible to
avoid impacts
with the vessel.
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