Application Research of Adjustable Frequency DC-Spark in Oil Analysis Spectrometer

In order to improve the excitation efficiency and stability of the oil analysis spectrometer, this paper studies the application of adjustable frequency DC-Spark in oil analysis spectrometer and the feasibility of the excitation source is verified. The adjustable frequency DC-Spark is based on PWM (pulse width modulation) technology. By controlling the duty cycle of the PWM to affect the frequency and average energy of the spectral excitation, the warm-up time is shortened and the excitation frequency is optimized. The performance of the adjustable frequency DC-Spark and the AC arc excitation source were tested respectively in an oil analysis spectrometer system based on the rotating disk electrode (RDE: rotation disk electrode). The standard oil of 0, 10, 50 and 100 ppm of Conostan company was tested. The experimental results show that compared with the AC arc excitation source, the adjustable frequency DC-Spark has better excitation and less heat generation. The test results of Fe, Cu and Mg elements in the 100 ppm oil were taken as examples; the repeatabilities were 3.6, 3.5 and 4.1, and the reproducibilities were 2.6, 5.1 and 1.5, which were better than the detection values of AC arc excitation source.