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Potentiometric Oxygen Sensor POS 2.0

Potentiometric Oxygen Sensor POS 2.0

The potentiometric oxygen sensor POS 2.0 is a Nernstian type electrochemical device for a wide oxygen partial pressure range from < 10-30 to > 1 atm. The sensor is based on the application of zirconia solid electrolytes which are selective oxygen ion conductors. The reference electrode is ambient air which is continuously supplied and may not be used up or changed as in the case of solid reference electrodes. All parts are solid and the measurement does not lead to an increase in the water vapor pressure as in the case of aqueous electrolytes. The sensor does not require maintenance.

The potentiometric oxygen sensor POS 2.0 measures with high precision and high imput impedance the cell voltage and converts this value into the oxygen partial pressure in atm. This is displayed by an LCD in large letters (25 mm).

The temperature of the active sensing element is controlled with high precision within a small range of ± 0.1 oC which allows a very precise determination of the oxygen partial pressure.

Potentiometric sensors are preferred over amperometric devices, especially when a large oxygen partial pressure range (several orders of magnitude) is to be covered and/or the oxygen partial pressure is controlled by the equilibrium of two or more gases (e.g., mixtures of CO, H2, CO2, H2O).

Alternatively to the integration of the sensor into the instrument, the sensor may come as a separate unit and may be directly exposed to the measuring gas without the requirement of supplying the gas to the instrument.

Typical Areas of Application

All applications in which an oxygen partial pressure is to be detected over a wide range, either directly by the presence of oxygen molecules or indirectly by the presence of two or more gases, which provide an oxygen equilibrium partial pressure, such as

- Oxygen partial pressure measurements in ambient and industrial environments
- Inert gas ("dry") boxes and chambers
- Control of CO2/CO (e.g., for metal hardening), H2O/H2 and other atmospheres
- Scientific and technological tasks of oxygen control and measurement


Applicable oxygen partial pressure range: < 10-30 atm - > 1 atm
Selective to the motion of oxygen ions
Response time: t90 < 30 sec
LC-display (3 1/2 digits) of the oxygen partial pressure in atm
Analogue output: 0 - 0.1 ... 10 V, linear with the logarithm of p(O2); 4 - 20 mA
Power supply: 220 V AC (50 - 60 Hz); 110 V AC (50 - 60 Hz) (optional)
Power consumption: max 150 W
Temperature control of the active sensor element ± 0.1 °C
Accuracy: < 0.2 % of log p(O2); ± 10 % for the entire measuring range
Cross sensitivity: only in the case of chemical reactions of other gas components
with oxygen at the sensor surface
Signal stability: ± 3 %/year
Warranty: 2 years


Sensor head: 2.5 cm in diameter x 4.5 cm in length
Read out box: w x h x d = 24.1 x 13.5 x 25.5 cm3
Weight: 2 kp