SoftwareSeveral software applications have been written and used to operate the hardware described in the previous section. This section is a description of the software used in the research. A software application that controlled the positioning system, waveform generator, power supply, and data acquisition of the CPD sensor was written in a LabView graphical programming environment (from National Instruments). . The Labview environment was chosen due to its ease of use in designing the GUI and the availability of all necessary libraries and drivers for Labview from the hardware manufacturer. The Labview also provided hundreds of built-in libraries for advanced analysis and data visualization. The written application communicated with the DAQ PC card and ISA indexer card installed in the PC to control the incoming CPD sensor data and its movement across a sample surface. A graphical user interface has also been provided to control the hardware, view and monitor signals, and configure measurement parameters. The application was used to post-process the data and visualize the surface analysis results in 2D and 3D views. A schematic diagram of the application is shown in Figure 3.17. Positioning System Software The positioning system manufacturer provided libraries of software routines to help develop programs for the 6400 Series Motion Controller. These libraries were compiled into Labview to make it usable in this environment. Figure 3.17: Schematic diagram of the Labview application. Using routines from compiled libraries, the application communicated via the PC ISA card with the indexer to control the speed, direction and acceleration of the CPD sensor movement....... middle of paper ......[7] Kelvin, “Contact Electricity of Metals”, Philosophical Magazine v46 (1898), p82[8] WA Zisman, “A new method of measuring contact potential differences in metals”, Review of Scientific Instruments, v3 n7 (1932) , p367[9 ] E. Zanoria, S. Danyluk, A. Zharin, C. Bhatia, “Potential contact measurements of hard drive surfaces in humid environments”, Journal of Vacuum Science & Technology A: Vacuum, Surfaces, Films v14 n1 (1996), p52[10] Hamall, K. "Non-contact measurement of wear-induced changes in surface potential", Master's thesis, Georgia Institute of Technology, Atlanta, 1996.[11] Watt A., “Marginal Field Corrections in nvCPD Applications,” Master's Thesis, Georgia Institute of Technology, 2004.[12] WRSmythe, Static and Dynamic Electricity, 2nd ed., McGraw-Hill, 1950[??] Landau LD, Livshits EM, “Electrodynamics of Continu Media”, Moscow: Nauka, 1982