We use TRENI (Total REactive Nitrogen Instrument), an NO chemiluminescence analyzer and an inlet system, to determine NO, NO2, NOy as well as NOz (peroxyacyl nitrates (PANs), organic nitrates (RONO2), and HNO3). The schematic diagram shows the main part of the instrument, the chemiluminescence analyzer. The chemiluminescence, produced by mixing NO and ozone, is detected by a PMT and photon counting system. The NO2 converter, a blue-light photolytic converter, converts NO2 to NO, to determine NO2. The NOy converter (Gold converter), heated gold tube, acts as a catalytic converter to convert NOy species to NO.

This instrument has a second inlet system which speciate NOy concentrations into NOx, peroxyacyl nitrates (PANs), organic nitrates (RONO2), and HNO3. The schematic diagram shows thermal decomposition inlets which are attached to the NO2 converter. 650°C, 400°C, 200°C, and ambient temperature are employed in the inlets to measure HNO3, organic nitrates, peroxyacyl nitrates and NOx, respectively (Day et al., 2002).