In search of the ultimate experiment for quantitative depth profile analysis in glow discharge optical emission spectrometry. Part II: Generalized method

Abstract The current and voltage terms of the SIMR approach are combined with the pressure approach of BHP to derive an empirical equation that describes the relationship between recorded emission signal and current, voltage and pressure in a model‐independent way. To test the equation, an emission line from each of five different elements in up to five different matrices recorded in all three operational modes of the glow discharge lamp for thirty different values of current, voltage and pressure were combined to give an average of 114 data points per line. The equation was then fitted to the data through multiple linear regression to derive a best estimate of the separate contributions of current, voltage and pressure to intensity and emission yield. The results show that current, voltage and pressure all contribute significantly to the recorded signals and emission yields. Typically, emission yield is proportional to current, decreases as the square root of over‐voltage and increases linearly with pressure at low pressures but decreases exponentially at higher pressures.