4.2 External power supply
A set comprising a Micro USB cable and wall mount is available (optional) for the external
power supply. The Micro USB cable can be connected to a PC or to the wall mount adapter
for electrical supply. If an external energy source is used, the battery symbol in the display is
replaced with "USB".
4.3 Sensor connection
temperature sensor
Sensor membrane
Connecting or removing the sensor on the instrument:
1. In order to connect the sensor to / from the equipment, the sensor connecting plug is con-
nected to the jack on the equipment and tightened clockwise. Please ensure that the nose
and the recess of the polarity reversal safeguard fit together correctly.
2. In order to remove the sensor from the device, the connecting plug is unscrewed anticlock-
wise and the plug is pulled out of the jack.
4.4 Sensor
The sensor of the SD 400 Oxi L is an optical oxygen sensor. The sensor is waterproof in ac-
cordance with IP67 and is equipped with an integrated temperature sensor. The durable cable
is connected to the measuring device by means of a 4-pin plug.
During measurement, it must be ensured that the temperature sensor is also fully immersed
in the sample.
During the measurement, it takes a while for equilibrium to be reached and the dissolved
oxygen is to be diffused through the membrane with the luminophores.
The membrane is sensitive and damages due to scratching, abrasion or from organic solutions
(e.g. acetone) falsify results.
The sensor must always be kept moist. For this purpose, the storage flask included in the
scope of delivery contents should be fitted on to the sensor and screwed tight (see also 6.2
Safekeeping). It can also be used as a calibration flask.
A Micro SD card, also included in the scope of delivery contents, contains the sensor-specific
calibration data.
The following parts are essential for oxygen measurement with the SD 400 Oxi L device:
1. Sensor membrane on the tip of the sensor: The optical fluorescence measurement for
oxygen measurement takes place at the tip of the sensor membrane.
2. Micro SD card: The relevant data for the sensor is stored on the SD card. If the SD card is
inserted in the measuring instrument, the serial number of the sensor membrane is displayed
when switched on. With replacement of the sensor membrane, the SD card should also be
replaced. It is included in the scope of delivery contents and can be found in the memory card
insert of the instrument (see the top of the next page).
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