Auto Power-Off; Backlighting; Calibration; General Information - Tintometer Lovibond SD 400 Oxi L Instrucciones

7.5 Auto Power-Off

The display P0 means that the automatic shut-down function is deactivated and the instru-
ment remains switched on continuously.
The display P1 means that the instrument switches off automatically after 10 minutes (after
the last use of a button).
We recommend activating the shut-down function in order to extend the service life of the
sensor and the batteries.
If the automatic shut-down function is activated (P1 display), a 30-second countdown is
shown in the display before the instrument switches off. You can then select with the arrow
keys (RIGHT/LEFT) whether the device should be switched off or not. The current settings
are selected by pressing the ENTER button and the instrument returns to measuring mode.
Alternatively, you can proceed to the date display with the RIGHT arrow key.
7.6 Backlight
The backlight of the display is switched on and off by pressing the ON/OFF button. The back-
lighting does not switch off automatically. In order to extend the battery life, we recommend
not leaving the light switched on continuously.

8 Calibration

8.1 General information

If no saturated air is available for a single-point calibration, the storage flask can be used to
obtain 100 % water-saturated air.
The dissolved oxygen concentration is dependent on the temperature (T), the pressure (BP)
and the salt content (S).
T means automatic temperature compensation (ATC); NO means that no temperature com-
pensation is performed.
BP means that the automatic pressure compensation is performed; NO means that no pres-
sure compensation is performed.
S means salinity and is defined as NaCl, Mg-sulphate and Ca-sulphate, etc., dissolved in water.
The salt concentration can be determined based on the conductivity. In order to be able to
consider the salt compensation in the measurement of the oxygen, the salt concentration is
entered in ppt (parts per thousand) or in mS/cm (see 7.3 "Salinity correction"). The oxygen
concentration is specified in consideration of the manually entered salt concentration as
saturation in %.
8.2 Single-point calibration
There are two possibilities for performing a single-point calibration:
1. Calibration in air-saturated water:
The water is continuously flushed with air by blowing the water with a fan until complete
saturation for a period of approximately 10 minutes.
The sensor is held in the air-saturated water until both the temperature and the oxygen display
(mg/l or Sat%) have reached a stable value.
If no air-saturated is available for a single-point calibration, the storage flask can be used to
obtain 100 % water-saturated air (see point 2).
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SD_400 Oxi L_1 01/2016