Design And Implementation Of Automatic Measurement System For Electrical Properties Of Rocks

Understanding the electrical properties of materials such as dielectric constant and conductivity has significant impact to materials science,medical application,geological remote sensing and so on.Due to the limitation of theoretical approach and methods,a complete system and methodology for the measurement of rock electrical properties have not been established yet.Nowadays,with the powerful functions of computation and control from the computer,the electrical properties measurement and analysis work for complicated materials can be achieved by using the platform of automatic control and digital analysis,thus a complete automatic measurement system for electrical properties of rocks and composite materials can be accomplished to improve the efficiency and accuracy of laboratory measurement.In this paper,an automatic measurement and analysis system for electrical properties of rocks using parallel-plate capacitor and impedance analyzer is designed and implemented.A design scheme for the proposed automatic measurement system is carried out by controlling an impedance analyzer HP4195 A and a parallel-plate capacitor sample holder with LabVIEW platform.Functions including data transmission and acquisition,algorithm embedding,result computation and analysis report creation are accomplished in this proposed system.Samples of various material and rock are tested in this system and a comparison has been made between automatic measurement results and manual measurement results.The error factors is evaluated and the dielectric dispersion phenomenon observed in the measurement of shale sample is also discussed in the paper.The proposed automatic measurement system solved the problem that the existedclassic model of electrical instrument with high measurement stability at low frequency,was not able to conduct an automatically measurementof the electric properties of rock samples.The experimental results show that a lot of advantages can be achieved by this automatic measurement system comparing with manual measurement,which including a shorter measurement period,higher efficiency,more stable and accurate results,and less interference from human and external factors.The proposed system provides convenience for experimental measurement of electrical properties of rocks and composite materials,and can be further applied to establish a database of rock’s physical properties.It can also provide professional rock physics measurement services to the industry and research institute,which has a promising market potential.