triOS Dissolved Oxygen, Руководство по эксплуатации

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D01-903en201912 Manual Dissolved Oxygen
Dissolved Oxygen //
Calibration
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Calibr
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Calibr
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Commissioning
Commissioning
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Technical
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Technical
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5.2 One-Point Calibration
The calibration in one point consists in propping up a 100% point : please consult chapter 5.1.2 (slope calibration).
5.3 Measurement Properties
5.3.1 Influences on the measurement
The oxygen measurement is dependent on the following parameters:
• The temperature of the measurement medium
• The air pressure (atmospheric pressure)
• The salinity of the measurement medium
The degree of solubility of oxygen in water is dependent on the temperature, the salinity, and the air pressure. This dependency
is stored in the sensor's measurement electronics in the form of functions. The sensor can therefore determine the oxygen
concentration of the measurement medium, in order to digitally transmit the influencing factors above, in compensated form,
to the transmitter/controller.
5.3.2 Temperature compensation
The temperature compensation is automatically managed by the sensor via the integrated temperature sensor (NTC).
5.3.3 Atmospheric pressure
With the most frequently used calibration method – end value calibration of the sensor in water vapor-saturated air – the air
pressure must be taken into account. For this purpose, the air pressure can, for example, be transmitted to the sensor by your
controller, where it is saved.
The default value of the atmosphere used for the compensation is 1013 hPa.
5.3.4 Salinity
The value for the salinity of the measurement medium could be transmitted to the sensor by your terminal.
The default value of the salinity used for the compensation is 0 g/Kg.
(1) Positioning in water vapor-saturated air