An empirical procedure, “LINT,” for relating emission line intensities of intrinsic impurity ions to their elemental contributions to the total, bolometric, radiation loss and the volume-averaged effective ion charge, Zeff, has been developed and applied to limiter plasmas in the JET tokamak. In this article we discuss extensions to the data base to include x-ray lines and continua intensities, applicable to a wider range of tokamak plasma configurations such as X-point plasmas and quasi-steady-state, edge-cooled ELMy H modes. Examples are shown of the technique applied to reference discharges during which the plasma configuration is changed continuously. The total data set, comprising line and continua irradiances, tomographic bolometry, and x-ray emission and Zeff imposes constraints on the diffusion parameters used in models of impurity ion transport. © 1999 American Institute of Physics.