Sensor for the selective detection of ammonia in no.sub.X -containing, oxygen-rich gases
AssigneeDornier GmbH
InventorsCarsten Plog, Werner Maunz, Ralf Mueller
Life of this patent
Estimating the term…
Abstract
A sensor for selective detection of ammonia in high-oxygen, NO.sub.x -containing gas. The sensor has a component part acting as the capacitor, and a gas-permeable sensitive layer as the dielectric, the sensitive layer being a hydrophobic, precious-metal-free zeolite of low acidity which has an ordered crystalline structure of primary-pores whose diameter is of the magnitude of the gas-kinetic diameter of NH.sub.3.
Claims18
A sensor for selective detection of ammonia in oxygen-rich, NO.sub.x -containing gas which comprises
- (a) a component part acting as a capacitor and
- (b) gas-permeable sensitive layer as a dielectric, the sensitive layer being a hydrophobic precious-metal-free zeolite of low acidity which has an ordered crystalline structure of primary pores whose diameter is of the magnitude of the gas-kinetic diameter of NH.sub.3.
A method for the selective detection of ammonia in oxygen-rich, NO.sub.x -containing gas, comprising:
- exposing the gas to a sensor comprising
- (a) a component part acting as a capacitor and
- (b) a gas-permeable sensitive layer as a dielectric, the sensitive layer being a hydrophobic precious-metal-free zeolite of low acidity which has an ordered crystalline structure of primary pores whose diameter is of the magnitude of the gas-kinetic diameter of NH.sub.3 ;
- measuring a change in resistance of the sensor;
- and
- correlating the change to a concentration of ammonia in the gas.
Dependencies are inferred from the claim text.