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

Quartz microbalance sensors coated with silicon-based polymers are fou nd to be extremely reliable for the detection of CO2 around 70-degrees -C. The optimization of our differently functionalized silicon-based p olymers leads to excellent sensor performances with a low detection li mit (<50 vpm). The response times in the order of 1 min can be optimiz ed 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 CO 2 in air. Small effects due to interferences from other gases are disc ussed finally.