A Comparison of Phenoldisulfonic Acid,Nondispersive Infrared,and Saltzman Methods for the Determination of Oxides of Nitrogen in Automotive Exhaust

The Saltzman Phenoldisulfonic Acid and Nondispersive Infrared methods have been compared for the determination of oxides of nitrogen in automobile exhaust. The main purpose of this investigation was to determine whether the Nondispersive Infrared method could be used as a possible replacement for the Saltzman method. Results show that the Nondispersive Infrared analyzer can be used to measure NO_x in exhaust gases with advantages over both the Saltzman and Phenoldisulfonic Acid methods. These advantages include simplicity, speed, less complicated analytical technique, and the fact that it is better adapted to be carried out by technicians at the test site.