Quant. anal. of laser-induced fluorescence (LIF) signals of NO requires properly accounting for the effects of temp., collisions, and laser and detection properties on the measured signals. Over the past, LIF properties of NO were studied for a range of conditions, from well-controlled burners to internal combustion engines. The knowledge gained from these studies was compiled into a model and software tool that now allows the computation of LIF spectra/signals for given exptl. conditions. The excitation dynamics are treated in a simplified fashion. The role of nonstationary excitation dynamics on the LIF signal is discussed using a comprehensive, time-dependent, multilevel rate equation model.