The decay of infrared fluorescence from IR multiphoton excited CDCl3 was studied as a function of incident fluence and pressure of added Ar. The decays were exponential and allowed for the calculation of the average energy transferred per collision, [[Delta E]], with Ar and with CDCl3, as a function of the average internal energy of excited CDCl3 using a direct method. Identical information was obtained following the inversion procedure developed by Barker et al. (Int. Rey. Phys. Chem. 1993, 12, 2, 305). Both sets of values agree well for a single value of the internal energy. The experimental results were also modeled using a master equation formulation to obtain [Delta E](d), confirming the predictive power of the model calculations. The increase of temperature of the gas mixture and its effect on the IR fluorescence signal were also analyzed.