Nitric oxide measurements in a flame by laser fluorescence

Laser fluorescence measurements have been performed to detect nitric oxide in a CH4–O2–N2 flame at atmospheric pressure. For these measurements a frequency-doubled tunable dye laser was used to excite the UV γ-bands of nitric oxide. Sensitivities were adequate to detect naturally occurring levels of nitric oxide that were in the 20–30-ppm range. Higher sensitivities can be achieved using other currently available lasers having greater output intensities.