Research Of Laser Energy Automatic Compensation In LIBS Measurement

In the field of element detection,LIBS online detection technology has been widely applied in many fields due to its advantages of real-time,fast and non-contact detection.In LIBS measurement system,the measurement accuracy is the most important part of the entire measurement process.In the actual measurement process,the measurement accuracy of LIBS will be affected by some external environmental factors or internal factors of laser.Through the study,it is found that due to the aging of the internal working substance of the laser and other external factors,the output stability of the laser energy also has a certain impact,thus causing a certain error for the subsequent quantitative analysis.Due to the laser’s change in laser energy during pulse discharge,there is a certain rule,in order to improve LIBS measurement accuracy,a energy compensation can be performed by a appropriate method based on this rule.This paper first summarizes the influence of laser energy on LIBS measurement precision and the current research status of laser energy output stability in LIBS measurement process,then the main factors affecting the measurement accuracy of LIBS are analyzed by studying the LIBS measurement process.Then the relationship between the laser energy and the intensity of the plasma line is studied from the perspective of the plasma generation mechanism.On the other hand,the effect of laser energy on the spectral line intensity and the quantitative analysis accuracy of the sample composition were studied by experimental methods.Then we studied the specific process of laser pulse generation by the laser to analyze the main factors that affecting the laser energy output,through the experimental method collects the laser energy and analyzes the variation law of laser energy through experimental data.A laser energy automatic compensation scheme was proposed,and a laser energy automatic compensation model was established to enable the laser energy output to be automatically stable within a certain threshold.Afterwards,the feasibility of automatic laser energy compensation method was verified by experimental methods.Finally,we brought the laser energy automatic compensation scheme into the LIBS measurement system,so we can improve the LIBS measurement accuracy by studying the energy-compensated sample line intensity signal and the quantitative analysis error of the sample element.