  A single molecule break junction device serves as a tunable model system for
probing the many body Kondo state. The low-energy properties of this state are
commonly described in terms of a Kondo model, where the response of the system
to different perturbations is characterized by a single emergent energy scale,
k_B*T_K. Comparisons between different experimental systems have shown issues
with numerical consistency. With a new constrained analysis examining the
dependence of conductance on temperature, bias, and magnetic field
simultaneously, we show that these deviations can be resolved by properly
accounting for background, non-Kondo contributions to the conductance that are
often neglected. We clearly demonstrate the importance of these non-Kondo
conduction channels by examining transport in devices with total conductances
exceeding the theoretical maximum due to Kondo-assisted tunneling alone.
