Contents 1 Introduction to measurement technology 11.1 History of measurement technology 11.2 Basic concepts of measurement technology 41.3 Applications of measurement technology 71.3.1 Industrial automation 71.3.2 Equipment monitoring 111.3.3 Quality performance inspection 121.3.4 Building monitoring and security system 131.3.5 Home and office automation 141.3.6 Other field applications 161.4 New trends in measurement technology 171.4.1 New sensors 171.4.2 Intelligent sensors 191.4.3 Virtual instrument 201.5 Manufacturers 212 General description of signal 272.1 Introduction 272.2 Classification of signal 272.3 Signal synthesis 332.4 Fourier decomposition of a sawtooth wave 352.5 Spectrum of periodic signal 372.5.1 Trigonometric Fourier series representation 372.5.2 Exponential Fourier series representation 442.6 Characteristics of periodic signal 482.7 Aperiodic transient signal 502.7.1 Definition of the Fourier transform 502.7.2 Properties of Fourier transform 552.7.3 Spectrums of typical aperiodic transient signals 612.8 Random signals 663 Characteristics of measuring systems 713.1 Introduction 713.1.1 Classification of measuring instruments 713.1.2 Description of the characteristics 753.1.3 Linear system and its main properties 763.2 Static characteristics 79 3.2.1 Accuracy 793.2.2 Precision 813.2.3 Range or span 813.2.4 Linearity 823.2.5 Sensitivity 823.2.6 Resolution 843.2.7 Bias 853.2.8 Dead zone 853.2.9 Threshold 853.2.10 Hysteresis 863.2.11 Drift 873.2.12 Repeatability 873.2.13 Stability 883.2.14 Tolerance 883.2.15 Error 883.3 Dynamic characteristics 883.3.1 Types of dynamic inputs 883.3.2 Physical meaning of convolution 893.3.3 Mathematical description 903.3.4 Series connection and parallel connection 1023.3.5 Mathematical models of the measuring systems 1033.4 Step responses of measuring system 1143.4.1 The response of the first order system 1143.4.2 The response of the second order system 1153.4.3 Transient response specifications 1173.5 Nondistortion measurement 1203.6 Identification of dynamic characteristics 1233.7 Loading effect 1273.8 Anti interference technology 1314 Signal conditioning�� processing and recording 1354.1 Introduction 1354.2 Bridge circuit 1354.2.1 Classification 1364.2.2 Stress and strain 1364.2.3 DC (Wheatstone) bridge circuit 1384.2.4 AC bridge circuit 1454.3 Modulation and demodulation 1534.3.1 Definitions 1534.3.2 Amplitude modulation process 1544.3.3 Frequency modulation 1624.3.4 Typical applications 1654.4 Filter 1694.4.1 Classification 169 4.4.2 Real filter 170 4.4.3 Low pass filter 173 4.4.4 High pass filter 175 4.4.5 Band pass filter 177 4.4.6 Filter bank 178 4.4.7 Typical applications 181 4.5 Sampling and aliasing 183 4.5.1 Sampling 183 4.5.2 Nyquist Shannon sampling theorem 1844.5.3 Aliasing 185 4.6 Displaying and recording signal 188 4.6.1 Analog and digital display 188 4.6.2 Pen strip chart recorder 189 4.6.3 Circular chart recorder 189 4.6.4 Paperless chart recorder 190 5 Correlation measurement 193 5.1 Introduction 193 5.2 Correlation analysis 193 5.2.1 Correlation coefficient 195 5.2.2 Autocorrelation function 197 5.2.3 Cross correlation function 200 5.3 Spectral analysis 203 5.4 Digital image correlation measurement 2045.4.1 Introduction 204 5.4.2 Basic principle of two dimensional DIC 2055.4.3 Applications of two dimensional DIC 2096 Sensors 211 6.1 Introduction 211 6.2 Temperature sensors 211 6.2.1 Thermocouple 212 6.2.2 Resistance temperature detector 213 6.2.3 Thermistors 216 6.2.4 Integrated circuit temperature sensors 2186.2.5 Infrared temperature sensors 219 6.2.6 Bimetallic temperature devices 220 6.3 Pressure sensors 221 6.3.1 Strain gauge pressure sensors 221 6.3.2 Piezoelectric pressure sensors 222 6.3.3 Piezoresistive pressure sensors 223 6.3.4 Capacitive pressure sensors 2256.3.5 Variable reluctance pressure sensors 2266.3.6 Potentiometric pressure sensors 2276.3.7 Bourdon tube pressure sensors 2286.4 Flow sensors 2306.4.1 Differential pressure flowmeter 2306.4.2 Turbine flowmeter 2336.4.3 Vortex flowmeter 2346.4.4 Thermal flowmeter 2356.4.5 Doppler ultrasonic flowmeter 2376.4.6 Transit time ultrasonic flowmeter 2386.4.7 Laser Doppler anemometer 2396.5 Displacement sensors 2406.5.1 LVDT displacement sensor 2406.5.2 Capacitive displacement sensor 2426.5.3 Inductive displacement sensor 2436.5.4 Laser displacement sensor 2446.5.5 Resistive displacement sensor 2466.5.6 Ultrasonic displacement sensor 2476.5.7 Gra