Solid-State Electrochemical Oxygen Sensor
1992; Taylor & Francis; Volume: 25; Issue: 5 Linguagem: Inglês
10.1080/00032719208020038
ISSN1532-236X
AutoresRobert S. Tieman, William R. Heineman,
Tópico(s)Advanced Chemical Sensor Technologies
ResumoAbstract A solid-state amperometric sensor with which oxygen can be determined electrochemically in a humid atmosphere is described. The sensor consists of three Pt electrodes screen-printed onto a 1 in × 1 in ceramic plate. One Pt strip is coated with Ag/AgCl to form a reference electrode. A thin coating of the hydrophilic polymer poly (dimethyldiallylammonium chloride), poly (DMDAAC), provides the ionic conductivity needed to carry charge within the electrochemical cell. Oxygen that diffuses into the polymer film is detected at a Pt electrode by reduction. The sensor has a steady state response tine to oxygen of less than 30 s when coated with a polymer film of >10 μm thickness and less than 15 s when coated with a 3 μm-thick film. The sensor response is linear in the range of 0-100% oxygen with a relative standard deviation between individual trials of 1% for up to three weeks, after which time the precision degrades. The sensor responds to oxygen over the temperature range of 25°C to 40°C.
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