Amperometric PbSnF 4 -based oxygen sensors: rapid response at room temperature in the operating pressure range 10 kPa–7.2 MPa

This paper describes the response characteristics and transient behaviour of a PbSnF4-based oxygen sensor at elevated pressure. The amperometric sensor has the structure: Ag|Ag6l4WO4|PbSnF4| sensing electrode, O2 in which the fast-ion conductors, Ag6l4WO4 and PbSnF4, and an iron(II) phthalocyanine-based sensing electrode were used. The sensors was capable of determining oxygen partial pressures of 10 kPa–1.9 MPa under high pressures ranging from 10 kPa to 7.2 MPa. The 90% response time was 35 s on average at room temperature. The sensor exhibited neither drift nor hysteresis under normal conditions, but did show pronounced asymmetrical transient characteristics with tailing for wide downward changes over 1½ decades of oxygen partial pressure.