A high voltage spark discharge was used to sample ferrous alloy samples in a point-to-plane configuration. An enclosed Petry spark stand was used so that the effluent from the spark could be put into a microwave discharge sustained at 2450 MHz. The emission from the eroded metals in the microwave discharge was monitored with a PARC Vidicon detector. This method of detection provided spectral simplification and improved signal-to-background ratios up to six-fold over the emission observed from the spark discharge. The emission from the microwave was shown to be linear with concentration for many lines observed.
