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 and sup-
plies the measuring device with electricity. 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 device:
1. In order to connect the sensor to the measuring device, the sensor connecting plug is con-
nected to the jack on the measuring device 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 device is an optical oxygen sensor. The sensor is waterproof in
accordance with IP67 and is equipped with an integrated temperature sensor. The long-lasting
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 little time for equilibrium to be reached and the dissolved
oxygen is 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 measurements.
The sensor must always be kept moist. For this purpose, the storage flask included in the
scope of supply is fitted on 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 supply 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 device, the serial number of the sensor membrane is displayed
when switching on. With replacement of the sensor membrane, the SD card is also replaced.
It is included in the scope of supply (see the top of the next page).
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SD_400 Oxi L_1 01/2016