Analyser for on-line and continuous measurement of dissolved oxygen traces.

HIGHER PERFORMANCES
Relative error : < + 5% or + 0,5 µg/l
Stability (1 day) : + 0,5%
Repeatability : < + 5%

OPERATION PRINCIPLE
The measurement principle of the oxygen analyser CITA 2021 is based on the use of a specific electro-chemical sensor (type HERSCH pile). The current delivered by the sensor is directly proportional to the oxygen concentration.
A temperature sensor (type Pt100) ensures the necessary compensation in temperature.

Thanks to its measurement principle linked to the absence of potential difference between the electrodes, the sensor is naturally independent of interfering elements present in boiler waters conditioning (complexants, re-decomposition products, hydrazine, dissolved H2). Its automatic calibration is carried out on-line (i.e. at the temperature, the pressure and the measurement flow). The oxygen standard is generated by water electrolysis and measurement flow. The response slope of the sensor is calculated by oxygen standard addition procedures which take account of the line concentration. (The calibration has, consequently, been made around the concentration measured before calibration.) The calibration results are recorded.

This calibration system takes into account :

• past calibrations,
• plausibility and acceptance criteria (e.g., calibration repeatability),
• detection of any calibration system failure.

LOWER COSTS
No conditioning products
No management and standard solutions use
Simplified and robust hydraulic circuit

ERGONOMICS
On-line help, Self-diagnostic
Fully automatic calibration
Built-in self-test
Dialogue and control by drop-down menus