Potentiostatic Oxygen Sensor POS 2.0

The potentiometric oxygen sensor POS 2.0 is based on the use of ceramic oxygen ion conductors with Nernst response behavior. The solid electrolyte has decisive advantages over conventional liquid electrolytes, e.g. selectivity for oxygen as the only mobile type of ion, non-solubility of other gaseous components, freedom from maintenance, non-release of water vapor into the medium to be measured and long-term stability.

There is a logarithmic relationship between the measured voltage and the oxygen partial pressure. The sensor is therefore particularly suitable if a large oxygen partial pressure range is to be covered (< 10-30 - > 1atm). The stress signal is independent of the geometry; There is therefore no need for special calibration. Ambient air (0.21 atm) is used as a reference; There is no change due to the consumption of the reference.

The voltage measurement is carried out in the control unit with high precision using a high impedance electrometer (< 1014 2). The temperature is regulated extremely precisely (# 0.1 °C) via a platinum heating element by controlling the resistance. The precise voltage measurement and temperature control currently achieve the highest possible accuracy of a potentiometric oxygen sensor.

The measured voltage is converted into the oxygen partial pressure by the control unit. This is shown on the large-format LCD display (digit height 2.5 cm) and is available proportionally to the output.

The sensor head is built into a housing through which the gas to be measured flows. A suitable pump with reducing valve is available as an accessory if required.

Typical areas of application

All applications in which the partial pressure of oxygen is to be measured selectively over several powers of ten, e.g

- Control of inert gases (e.g. in protective gas boxes, to avoid oxidation in electronics and in food packaging)

- Control of breathable gases (e.g. in fermentation cellars and in the room air)

- Exhaust gas testing (e.g. for motor vehicles and combustion systems)

- Process control

Specifications

Applicable oxygen partial pressure range: <10E-30 - > 1 atm

Selective for oxygen (primary)

Response time: t90 < 30 s

LCD display: 3 1/2 digits, oxygen partial pressure in atm

Analog output: 0-0.1 ... 10 V, linear with the logarithm of p(02); 4 - 20 mA

Power consumption: max 150 W

Heating element temperature control: +-0.1°C

Accuracy: <0.2% of log p(02); +- 10% over the entire measuring range

Cross sensitivity: Only in the case of chemical reactions of other gas components with oxygen on the sensor surface

Signal stability: +-3%/year

Warranty: 2 years

Dimensions

Sensor head: 2.5cm diameter x 4.5cm height

Sensor control and display unit: WxHxD=23.5 x13.5 x26 cm'

Weight: 2kg