Generator malfunctions detected by radiation waveforms.

Radiation waveforms show the variation of x-ray intensity with time. Acceptance testing was done on 15 newly installed x-ray units and the waveforms of seven showed a total of 13 generator-related faults. Of the 13 faults, six would have caused inconsistently exposed radiographs in four units. These faults were corrected before the units were used clinically. After one year of use, the waveforms from five of the 15 units showed serious malfunctions. This illustrates the need for acceptance testing, radiation waveform monitoring and an active generator quality control program.