Dj. Slater et al., A BIELECTROLYTE SOLID-STATE SENSOR WHICH DETECTS SO3 INDEPENDENTLY OFO-2 - IMPLICATIONS FOR A SO2 SENSOR, Solid state ionics, 86-8, 1996, pp. 1063-1067
A solid-state sensor based upon a Na2SO4-NASICON couple surrounded by
yttria-stabilized zirconia (YSZ) is shown to respond to changes in P-S
O3 independently of P-O2 and P-SO2. In this mode, both electrodes are
exposed to the same test gas eliminating the need for a separate refer
ence compartment. This greatly increases the life of the sensor. The s
ame sensor has been successfully adapted to measure SO2 by utilizing a
catalyst to convert SO2 to SO3 by a factor which is constant at a giv
en P-O2 and temperature as governed by thermodynamic equilibrium.