[en] The effects of electron-density variations on population distributions of excited atomic states in a plasma have been studied. For specific conditions, an analytic expression is derived between excitation and electron temperatures. It has been found that the ratio of the ionization rate of the excited atom to the rate of electron-density variation plays an important role in the temperature difference. When this ratio is of order unity, the temperature difference is significant. However, when this ratio is large or small compared with unity, the two temperatures are nearly equal. These predictions are investigated experimentally. (author)