tailieunhanh - Multisensor thiết bị đo đạc thiết kế 6o (P4)

LINEAR SIGNAL CONDITIONING TO SIX-SIGMA CONFIDENCE INTRODUCTION Economic considerations are imposing increased accountability on the design of analog I/O systems to provide performance at the required accuracy for computerintegrated measurement and control instrumentation without the costs of overdesign. Within that context, this chapter provides the development of signal acquisition and conditioning circuits, and derives a unified method for representing and upgrading the quality of instrumentation signals between sensors and data-conversion systems | Multisensor Instrumentation 6a Design. By Patrick H. Garrett Copyright 2002 by John Wiley Sons Inc. ISBNs 0-471-20506-0 Print 0-471-22155-4 Electronic 4 LINEAR SIGNAL CONDITIONING TO SIX-SIGMA CONFIDENCE 4-0 INTRODUCTION Economic considerations are imposing increased accountability on the design of analog I O systems to provide performance at the required accuracy for computer-integrated measurement and control instrumentation without the costs of overdesign. Within that context this chapter provides the development of signal acquisition and conditioning circuits and derives a unified method for representing and upgrading the quality of instrumentation signals between sensors and data-conversion systems. Low-level signal conditioning is comprehensively developed for both coherent and random interference conditions employing sensor-amplifier-filter structures for signal quality improvement presented in terms of detailed device and system error budgets. Examples for dc sinusoidal and harmonic signals are provided including grounding shielding and noise circuit considerations. A final section explores the additional signal quality improvement available by averaging redundant signal conditioning channels including reliability enhancement. A distinction is made between signal conditioning which is primarily concerned with operations for improving signal quality and signal processing operations that assume signal quality already at the level of interest. An overall theme is the optimization of performance through the provision of methods for effective analog design. 4-1 SIGNAL CONDITIONING INPUT CONSIDERATIONS The designer of high-performance instrumentation systems has the responsibility of defining criteria for determining preferred options from among available alternatives. Figure 4-1 illustrates a cause-and-effect outline of comprehensive methods that are developed in this chapter whose application aids the realization of effective signal conditioning circuits. In .