Pyrolysis-electrochemical sensor for monitoring carbonyl sulfide levels in ambient air

摘要

A pyrolyzer-electrochemical cell-based sensor (MIDAS) gas detector, Honeywell Analytics) has been tested for its ability to detect carbonyl sulfide (COS) in ambient air. The unit employs pyrolysis to initially convert COS to hydrogen sulfide (H_2S) in the presence of ambient moisture and subsequently measures the H_2S response using an electrochemical sensor cartridge. The sensor proved to be linear in the range tested (50-100ppm) with a response ranging from 12-14% of the COS concentration depending upon relative humidity (RH). A 15% increase in response was observed as relative humidity increased from 1 to 100%.