Patent ID: 7442555

Claim:
A method of detecting the concentration of ammonia in a gas comprising the steps of: receiving a source stream of gas; splitting the source stream of gas into first and second streams of gas; absorbing SO 2 from at least one of said first and second streams of gas; exposing one of said first and second streams of gas to a first catalyst system under conditions capable of converting NH 3 present in the gas to N 2 ; exposing the remaining one of said first and second streams of gas to a second catalyst system under conditions capable of converting NH 3 present in the gas to NO; exposing each of said first and second streams of gas through a third catalyst system to establish a steady state equilibrium concentration ratio between NO and NO 2 ; detecting the levels of NO x present in said first and second streams of gas; and calculating the difference in NO x concentrations between said first and second streams of gas.