Abstract: The emission of the various electron guns of a color cathode ray tube are measured and indicated by a time sharing multiplexing technique where emission generating voltages are fed to the electrodes of the various electron guns in rapidly repeated sequence and the degree of emission thereof is displayed simultaneously on the faces of current meters responsive to average current flow. Such a technique permits simultaneous display of emission current for in-line cathode ray tubes having commonly connected control and/or accelerator electrodes, where individually adjustable spot cut-off voltages are sequentially connected to the set of commonly connected electrodes involved in synchronism at any given instant with the connections of the cathode electrode thereto which is to be assigned to the adjustable voltage involved.