RELIABLE CO2 SENSORS WITH SILICON-BASED POLYMERS ON QUARTZ MICROBALANCE TRANSDUCERS

Quartz microbalance sensors coated with silicon-based polymers are found to be extremely reliable for the detection of CO2 around 70-degrees-C. The optimization of our differently functionalized silicon-based polymers leads to excellent sensor performances with a low detection limit (<50 vpm). The response times in the order of 1 min can be optimized by adjusting optimum operation temperatures. The sensors have been used for more than nine months without significant loss in sensitivity, reversibility and reproducibility in the continuous monitoring of CO2 in air. Small effects due to interferences from other gases are discussed finally.