  Collisional and radiative dynamics of a plasma is exposed by so-called
Collisional Radiative Models [1] that simplify the chemical kinetics by
quasi-steady state assignment on certain types of particles. The assignment is
conventionally based on the classification of the plasma species by the ratio
of the transport to the local destruction frequencies. We show that the
classification is not exact due to the role of the time-dependent local
production, and a measure is necessary to confirm the validity of the
assignment. The main goal of this study is to evaluate a measure on the
quasi-steady state assumptions of these models. Inspired by a chemical
reduction technique called Intrinsic Low Dimensional Manifolds [2, 3], an
estimate local source is provided at the transport time-scale. This source is a
deviation from the quasi-steady state for the particle and its value is
assigned as an error of the quasi-steady state assumption. The propagation of
this error on the derived quantities is formulated in the Collisional Radiative
Models. Based on the error a novel technique is proposed to discriminate the
quasi-steady states. The developed analysis is applied to mercury and argon
fluorescent lamps separately and the corresponding errors are presented. We
observe that the novel and conventional technique agrees for most of the
excited levels but disagrees for a few low energy excited states.
