Research Of Lubricating Oil Spectrum Excitation System Based On Constant Voltage And Frequency Conversion DC-Spark Source

Atomic Emission Spectroscopy(AES)detection method has got promotion and popularization in our country Since the 1950 s.Especially,it has been widely used in geological,metallurgical,machinery and other departments.Performance of AES instrument and analysis technology are increasing as well.With the rapid development of Chinese industrial level,it appears especially important that how to keep the mechanical equipment long period and healthy running.Lubricating oil is the ‘blood' of the mechanical equipment.It can be very good for equipment running status monitoring that through the detection and analysis of metal wear analysis in lubricating oil.Therefore,it will be of great practical significance in the process of social production that combines the AES instrument and test analysis for lubricating oil.This thesis studies on the lubricating oil excitation system of AES detection equipment based on the constant voltage and frequency conversion technology.It develops a set of constant voltage and frequency conversion DC-Spark source and the excitation mechanism.The main contents are as follows:1.The development of the excitation source: at the beginning of the study,using the commercially available AC-Arc source.Oil sample is easy to catch fire during the process because arc average energy is too large.It is not good for spectrum acquisition and its security is low.So we decide to transform the AC-Arc source to the AC-Spark source,improving the peak energy and reducing arc average energy,which improves the degree of excitation spectra and security.The excitation spectrum is not stable from the AC-Spark source,and its frequency and impulse current are uncontrolled.For these reasons,the constant voltage and frequency conversion DC-Spark source is designed finally.It makes full use of the advantageous features of spark discharge and discharge frequency is variable.Discharge pulse current is from 10 to 50 ampere.Compared to the traditional spark source,it has a lower detection limit and its excitation spectrum is more stable.It can meet the demand of different analysis.In the meantime,its structure is novel and flexible,whose volume decreases in some extent.2.The development of the excitation mechanism: Based on the Rotating Disk Electrode(RDE),an excitation device is designed with the software Solid Works.According to the oxidation problem of the metal material during the long term spark excitation,choosing the W-Cu material with high performance finally.The structure of the excitation device has the adv antages of novel and flexible,which can realize the solid or liquid sample excitation.It ensures the accuracy of spectrum as well as operate s simply and quickly.3.Based on the designed excitation source and excitation device,combined with the assembled miniature UV spectrometer,the lubricating oil spectrum excitation system is set up.According to the American association of material and test standard(ASTM-D6595),detecting the lubricating oil by the designed system.The test results show that the me asured values of repeatability and reproducibility error are within the scope of the permit.The test data of the lubricating oil spectrum excitation system is qualified,so it can satisfy the need of actual test analysis for lubricating oil.