1st Edition

Instrumentation Design Studies

By Ernest Doebelin Copyright 2010
    728 Pages 457 B/W Illustrations
    by CRC Press

    726 Pages 457 B/W Illustrations
    by CRC Press

    Integrating physical modeling, mathematical analysis, and computer simulation, Instrumentation Design Studies explores a wide variety of specific and practical instrumentation design situations. The author uses MATLAB® and SIMULINK® for dynamic system simulation, Minitab® for statistical applications, and Mathcad for general engineering computations. Rather than consult the extensive manuals of these software packages, readers can access handy, sharply focused material in the appendices to assist in comprehension.

    After introducing the techniques behind the design of experiments (DOE), the book discusses several technologies for implementing vibration isolation, the design of a high-accuracy pressure transducer, and the use of cold-wire thermometers for measuring rapidly fluctuating fluid temperatures. It then focuses on a basic piezoelectric actuator that provides translational motions up to about 1mm full scale with nanometer resolution, before covering instruments used to measure the viscosity of liquids as well as two special classes of microphones (infrasonic and ultrasonic) and their important specialized applications. The book also presents statistical tools, such as hypothesis testing and confidence intervals, for experiments; the design and applications of thrust stands for measuring vector forces and torques; and the analysis and simulation of a shock calibrator. It concludes with a discussion of how shock testing machines can help reduce or prevent mechanical failures.

    Spanning system dynamics, measurement, and control, this book addresses the needs of practicing engineers working in instrumentation fields. It focuses on instruments for various applications, from geophysics to mechanical and aerospace engineering.

    Introduction to Statistical Design of Experiments: Experimental Modeling of a Cooling System for Electronic Equipment
    Basic Concepts
    Mathematical Formulation
    Full Factorial and Fractional Factorial Experiments
    Run-Sequence Randomization
    Validation Experiments
    Example Experiment: Modeling an Electronics Cooling Process
    Using Minitab to Design the Experiment and then Analyze the Results
    Multiple Regression: A General Tool for Analyzing Experiment Data and Formulating Models

    Vibration Isolation for Sensitive Instruments and Machines
    Passive Spring/Mass Isolators
    Passive Air Spring Systems
    Active Air Spring Systems
    Low-Frequency Isolation Using Negative-Spring-Constant Devices
    Active Electromechanical Vibration Isolation
    Tuned Vibration Absorbers and Input-Shaping Methods

    Design of a Vibrating Cylinder, High-Accuracy Pressure Transducer
    Basic Concept
    Cylinder Natural Frequency Calculations
    Use of an Unstable Feedback System to Maintain Continuous Oscillation
    Simulation of the Complete System
    Ultra-Precision Calibration/Measurement Using a 15-Term Calibration Equation, Built-in Temperature Compensation, and Microprocessor Data Reduction

    A Fast ("Cold-Wire") Resistance Thermometer for Temperature Measurements in Fluids
    Circuitry and Wire Details
    Estimating the Self-Heating Error
    Estimating the Sensitivity to Desired and Spurious Inputs
    Dynamic Response to Fluid Temperature Fluctuations
    Use of Current Inputs for Dynamic Calibration
    Electronic Considerations
    Effect of Conduction Heat Transfer at the Wire Ends

    Piezoelectric Actuation for Nanometer Motion Control
    Mechanical Considerations
    Actuators, Sensors, and Mounting Considerations
    Control System Design

    Preliminary Design of a Viscosimeter
    Definition of Viscosity
    Rotational Viscosimeters
    Measurement of Torque
    Dynamic Measurements
    Velocity Servos to Drive the Outer Cylinder
    Corrections to the Simplified Theory
    Non-Newtonian Fluids
    The Concept of the Representative Radius
    The Concept of Effective Length
    Cylinder Design According to German Standards
    Designing a Set of Cylinders
    Temperature Effect on Viscosity
    Temperature Control Methods
    Uncertainty Analysis
    Encoder Angular Position and Speed Measurement
    Practical Significance of the Shear Rate
    Fitting a Power-Law Model for a Non-Newtonian Fluid

    Infrasonic and Ultrasonic Microphones
    Infrasonic Microphones
    Diaphragm Compliance Calculation
    Microphone Transfer Function
    System Simulation
    Adjusting Diaphragm Compliance to Include Air-Spring Effect
    Wind Noise Filtering with Pipes and Spatial Arrays
    Ultrasonic Microphones
    Ultrasonic Acoustics Pertinent to Leak Detection

    Some Basic Statistical Tools for Experiment Planning
    Checking Data for Conformance to Some Theoretical Distribution
    Confidence Intervals for the Average (Mean) Value
    Comparing Two Mean Values: Overlap Plots and Confidence Intervals
    Confidence Intervals for the Standard Deviation
    Specifying the Accuracy Needed in Individual Measurements to Achieve a Desired Accuracy in a Result Computed from Those Measurements

    Multi-Axial Force/Torque Measurement: Thrust Stands for Jet and Rocket Engines
    Dynamics of Thrust Stand Force/Torque Measurement
    Dynamic Response Equations of the Thrust Stand
    Matrix Methods for Finding Natural Frequencies and Mode Shapes
    Simulink Simulation for Getting the Time Response to Initial Conditions and/or Driving Forces/Moments
    Frequency Response of the Thrust Stand
    Matrix Frequency Response Methods
    Simulation of the Asymmetric System: Use of Simulink Subsystem Module
    Static Calibration of Thrust Stands
    Damping of Thrust Stands
    Flexure Design

    Shock Calibrator for Accelerometers
    Description of the Calibrator
    Review of Basic Impact Calculations
    Simulation of the Coefficient of Restitution Experiment
    Some Analytical Solutions
    Simulation of the Pneumatic Shock Calibrator Apparatus
    Concluding Remarks

    Shock Testing and the Shock Response Spectrum (SRS)
    Analysis and Simulation of Response to Shock Inputs
    The SRS
    Practical Shock Testing and Analysis
    Vibration Shakers as Shock Pulse Sources
    Design of a Shock Isolater
    Relation of SRS to Actual Mechanical Damage
    Measurement System and Data Acquisition/Processing Considerations

    Appendix A: Basic MATLAB/SIMULINK Techniques for Dynamic Systems
    Appendix B: Basic Statistical Calculations Using Minitab


    Ernest O. Doebelin is Professor Emeritus in the College of Engineering at Ohio State University, where he received the Alumni Award for Distinguished Teaching and the Charles E. MacQuigg Award for Outstanding Teaching.