Study On Intelligentized Noble Gas Isotopes Measurement System

The isotopes measurement of the Noble gas is extensively applied in Earth System Science (ESS), while Ar-Ar is one of the most broadly utilized measurement methods in geochronology. Measuring in a faster and accurate way is the recent trend. However, the traditional manual methods not only consume a lot of time and labor, but also introduce some inaccurate factors that are easily affected artificially. Nowadays, Noble Gas Isotope Laboratories abroad mostly have automated their measurement sequence. In China, only the 40Ar/39Ar Laboratory of Beijing University has realized automatic measurement, but its control system was completely transplanted from Berkeley Geochronology Center, California, US.To fill the gaps in this domain, according to the available mass spectrograph equipment of Ar-Ar Geochronology Laboratory, Institute of Geology and Geophysics Chinese Academy of Sciences (IGCAS) and College of Precision Instrument and Opto-electronics Engineering of Tianjin University have begun cooperating with each other on Chinese Academy Scientific Research Instrument Innovation Project– Intelligentized Noble Gas Isotopes Measurement System, guiding the research on intelligentized measurement system.In this paper, the following topics are discussed.1. Depending on the precise two-dimension specimen platform, this new system will be able to position the processing samples and to focus the laser imaging system automatically. Improvement has been performed to the"Christmas Tree"specimen handling system of the Furnace: long time continuous automatic operation, multi samples treatment, automatic specimen handling even under high temperature.2. A new purification system is redesigned, it decreases the system volume greatly and hence increases its sensitivity and SNR (Signal Noise Ratio). Purification system automation are implanted by establishing auto valve groups, and opening/closing them with the programs, using the condition feedbacks, judgments, and safeties.3. Manual/automatic dual control function is added. The electric automatic control system based on PLC (programmable logic controller) is designed to respond manual operation, to synchronize manual and auto operations, and to be used to drive the actuator directly. Not only the following protections, power failure protection, vacuum protection, temperature ultra difference protection are added, but also the onsite and remote alarm function can be started automatically.4. By analyzing the previous ion counting cards, the new cards are designed it can driven in Windows XP. The existed algorithm is updated, the data automatic processing is perfected.5. Research on the two-dimension color image examination technology in the laser vision system, this thesis designs a new recognition method of sample ablating location for this system; applies a new color image vector filter which combined the medium filter and averaging filter; puts forward a applicable color image focusing evaluation algorithm and a camera auto-focus algorithm for this system; according to intelligent laser ablation, designs two sets of system calibration programs for camera calibration, system zero calibration and worktable zero calibration.6. The original control software compiled with Delphi is replaced by a new one based on LabVIEW 8.0, which can control the entire ablation process. This new software redesigns the auto focusing to increase its accuracy, and finally achieved the intelligent automatic sample melting by improving manual sample ablation process, auto distribution and automatic specimen melting via designed route.7. Control the sample ablation system, purification system, and mass spectrograph via one computer, replace the control software based on Modular 2, re-program each subprogram with LabVIEW 8.0, and design the main program correspondingly to control every part and therefore automate the whole process. Depending on each part's automation and real-time monitoring, coordinate intelligently and control centrally the entire system's test, enabling the mass spectrograph system to reach its best working status.8. Conduct experiments and analyze the sources of system errors to certify the feasibility and accuracy of the improvements and used method.