FCX-MCxx-CH for Low-Maintenance Oxygen Measurements

Measurement of oxygen in the air can be done by various physical processes. The modules presented here are zirconica solid electrolyte sensors working on the current-limiting principle. Unlike conventional solid electrolyte sensors, these sensors do not require any reference air. This decisive advantage offers a simple method of measuring the current oxygen content without the need for yearly maintenance. Other advantages are the low operating temperature of the zirconia of max. 400 °C, and the power consumption of just 3 W for the entire module. Measurement ranges of 0…25 and 95 % are available with a precision of 0.1 % O2, even under ambient pressures of -700 mbar to +4 bar. The sensor may be mounted either directly on the PCB inside a flow casing, or alternatively via a cable of up to 5 m in length. In the case of this second variant, measurements may also be made with gas temperatures of up to 300 °C. The electronics are flexible in use too: with a supply of 11,5…28 VDC models are available ranging from simple analog and (of course) linear voltage or current output signals, through to RS232, RS485, and naturally also I2C-bus.

Typical uses are wherever a long operating life of the sensor without constant recalibration is needed. This includes such areas as medical and biological systems, food processing systems, refrigeration technology, CO2-incubators, and personal safety.