Measurements of the continuum emission of an inductively coupled plasma in argon have been carried out. The mechanisms responsible for this radiation show different electron-density-dependences. By interrupting the power that is followed by a decay of the electron density, it is possible to unravel these different mechanisms. From the measurements it is concluded that the electron-atom interactions are in general of equal importance to the electron-ion interactions in creating continuum radiation. The relative contribution of the electron-atom interactions depends on the conditions of the plasma. Furthermore, the measurements show that the cross section for electron-atom momentum transfer deduced from our experiment using the formula for electron-atom free-free continuum radiation is not in agreement with the literature.