TABLE 108.5 Automated Measurement Factors Factor Consideration Frequency response measurements require use of a leveled generator. Alternatively, store a calibration curve. plexing multiple nodes require lead switching to shared instruments; consider these effects. Sampling frequency Must exceed the Nyquist frequency Include an anti-aliasing filter Manual instruments typically use od noise rejection over integer numbers f line cycles. Faster sampling rates for ATE are achieved using successive-approximation or other chniques. User may have to perform averaging as a post-processing step in order to achieve acceptable signal-to-noise ratios. Allow sufficient time for transients to settle for both stimulus/response instruments and device under test. Automatic measurements can produce large arrays of data at high speeds. Actual throughput to a hard disk may be much less than the maximum sampling rate of a data acquisition element(plug- in board, external instrument) Triggering Choices between free-running, external, and internal. Defining Terms Instrument: The means for monitoring or measuring physical variables Usually includes transducers, signal Measurement system: The sum of all stimulus and response instrumentation, device under test, interconnect, nvironmental variables, and th among the element Transducer: A device that transforms one form of energy to an electrical output that can be processed by an Instrument Virtual instrument: An instrument created through computer control of instrumentation resources with analysis and display of the data collected. Related Topics 3.1 Voltage and Current Laws.8.5 Sampled Data.73.2 Noise. 112.1 Introduction References N. Ahmed and T. Natarajan, Discrete-Time Signals and Systems, Reston, Vir ; Reston Publishing, 1983 E.O. Doebelin, Measurement Systems: Application and Design, 4th ed, New York: McGraw-Hill, 1990 J.P. Holman, Experimental Methods for Engineers, 6th ed, New York: McGraw-Hill, 1994 A D. Khazan, Transducers and Their Elements: Design and Application, Englewood Cliffs, N J. Prentice-Hall, 1994. H.W. Ott, Noise Reduction Techniques in Electronic Systems, 2nd ed, New York: John wiley Sons, 1988 w.J. Tompkins and J.G. Webster, Eds, Interfacing Sensors to the IBM PC, Englewood Cliffs, N J. Prentice-Hall, Further information The monthly journals, IEEE Transactions on Instrumentation and Measurement, and IEEE Transactions on Biomedical Instrumentation, report advances in instrumentation. For subscription information, contact: IEEE Service Center, 445 Hoes Lane, PO Box 1331, Piscataway, NJ 08855-1331.(800)678-IEEE. Information about automatic test equipment and software for data ition, analysis, and display, can be obtained from several vendors; for example, Hewlett-Packard, Englewood, CO,(800)-829-4444; Keithley Metrabyte, Taunton, MA, (800)348-0033; and National Instruments, Austin, TX, (512)794-0100. Information about transducers can be obtained from Omega International, Stamford, CT, (203)359-1660 e 2000 by CRC Press LLC© 2000 by CRC Press LLC Defining Terms Instrument: The means for monitoring or measuring physical variables. Usually includes transducers, signal conditioning, signal processing, and display. Measurement system: The sum of all stimulus and response instrumentation, device under test, interconnect, environmental variables, and the interaction among the elements. Transducer: A device that transforms one form of energy to an electrical output that can be processed by an instrument. Virtual instrument: An instrument created through computer control of instrumentation resources with analysis and display of the data collected. Related Topics 3.1 Voltage and Current Laws • 8.5 Sampled Data • 73.2 Noise • 112.1 Introduction References N. Ahmed and T. Natarajan, Discrete-Time Signals and Systems, Reston, Vir.:, Reston Publishing, 1983. E.O. Doebelin, Measurement Systems: Application and Design, 4th ed., New York: McGraw-Hill, 1990. J.P. Holman, Experimental Methods for Engineers, 6th ed., New York: McGraw-Hill, 1994. A.D. Khazan, Transducers and Their Elements: Design and Application, Englewood Cliffs, N.J.: Prentice-Hall, 1994. H.W. Ott, Noise Reduction Techniques in Electronic Systems, 2nd ed., New York: John Wiley & Sons, 1988. W.J. Tompkins and J.G. Webster, Eds., Interfacing Sensors to the IBM PC, Englewood Cliffs, N.J.: Prentice-Hall, 1988. Further Information The monthly journals, IEEE Transactions on Instrumentation and Measurement, and IEEE Transactions on Biomedical Instrumentation, report advances in instrumentation. For subscription information, contact: IEEE Service Center, 445 Hoes Lane, PO Box 1331, Piscataway, NJ 08855-1331. (800) 678-IEEE. Information about automatic test equipment and software for data acquisition, analysis, and display, can be obtained from several vendors; for example, Hewlett-Packard, Englewood, CO, (800)-829-4444; Keithley￾Metrabyte, Taunton, MA, (800) 348-0033; and National Instruments, Austin, TX, (512) 794-0100. Information about transducers can be obtained from Omega International, Stamford, CT, (203) 359-1660. TABLE 108.5 Automated Measurement Factors Factor Consideration Leveling Frequency response measurements require use of a leveled generator. Alternatively, store a calibration curve. Multiplexing Measurements from multiple nodes require lead switching to shared instruments; consider these effects. Sampling frequency Must exceed the Nyquist frequency. Include an anti-aliasing filter. Manual instruments typically use integrating (dual-slope) analog-to-digital converters which give good noise rejection over integer numbers of line cycles. Faster sampling rates for ATE are achieved using successive-approximation or other techniques. User may have to perform averaging as a post-processing step in order to achieve acceptable signal-to-noise ratios. Settling time Allow sufficient time for transients to settle for both stimulus/response instruments and device under test. Storage Automatic measurements can produce large arrays of data at high speeds. Actual throughput to a hard disk may be much less than the maximum sampling rate of a data acquisition element (plug-in board, external instrument). Triggering Choices between free-running, external, and internal