Sensors in Science and Technology: Functionality and Application Areas

Preface
Contents
List of Contributors
1: Sensor Systems
1.1 Definition and Mode of Operation
1.2 Classification
2: Physical Effects of Sensor Use
2.1 Piezoelectric Effect
2.1.1 Principle of Operation and Physical Description
2.1.2 Materials
2.1.3 Applications
2.2 Resistive and Piezoresistive Effect
2.2.1 Operating Principles and Physical Description
2.2.2 Resistive Effect and Its Application by Means of SGs
2.2.3 Piezoresistive Effect and Its Application by Silicon Semiconductor Elements
2.2.4 Materials
2.3 Magnetoresistive Effect
2.3.1 Principle of Operation and Physical Description
2.3.1.1 AMR (Anisotropic Magneto Resistance)
2.3.1.2 GMR (Giant Magneto Resistance)
2.3.1.3 CMR (Colossal Magneto Resistance)
2.3.1.4 TMR (Tunnel Magneto Resistance)
2.3.2 Advantages of XMR Technology
2.3.3 Applications of XMR Technology
2.4 Magnetostrictive Effect
2.4.1 Principle of Operation and Physical Description
2.4.2 Advantages of Magnetostrictive Sensor Technology
2.4.3 Applications of Magnetostrictive Sensor Technology
2.5 Effects of Induction
2.5.1 Principle of Operation and Physical Description
2.5.1.1 Law of Induction
2.5.1.2 Generation of Eddy Currents in Electrically Conductive Materials
2.5.1.3 Electromagnetic Oscillating Circuits
2.5.2 Advantages of Inductive Sensor Technology
2.5.3 Applications of Inductive Sensor Technology
2.6 Effects of Capacitance
2.6.1 Principle of Operation and Physical Description
2.6.1.1 Capacitor and Capacitance
2.6.1.2 Capacitance in the Alternating Current Circuit
2.6.2 Advantages of Capacitive Sensor Technology
2.6.3 Applications of Capacitive Sensor Technology
2.7 Gaussian Effect
2.7.1 Principle of Operation and Physical Description
2.7.2 Application of the Gaussian Effect
2.8 Hall Effect
2.8.1 Principle of Operation and Physical Description
2.8.2 Application of the Hall Effect
2.9 Eddy Current Effect
2.9.1 Principle of Operation and Physical Description
2.9.2 Application of the Eddy Current Effect
2.10 Thermoelectric Effect
2.11 Thermoresistance Effect
2.11.1 Principle of Operation and Physical Description
2.11.1.1 Thermal Response Times
2.11.1.2 Self-heating and Measuring Current
2.11.2 Advantages of Sensor Technology with the Thermoresistance Effect
2.11.3 Fields of Application
2.12 Temperature Effects in Semiconductors
2.12.1 Principle of Operation and Physical Description
2.12.2 PTC Thermistors (PTC Resistors)
2.12.2.1 Physical Context
2.12.2.2 Advantages and Application Areas
2.12.3 Thermistors (NTC Resistors)
2.12.3.1 Advantages and Application Areas
2.13 Pyroelectric Effect
2.13.1 Principle of Operation and Physical Description
2.13.2 Materials
2.13.3 Applications
2.14 Photoelectric Effect
2.14.1 Operating Principles and Physical Description
2.14.1.1 Outer Photoelectric Effect
2.14.1.2 Inner Photoelectric Effect: Photoconductor
2.14.1.3 Internal Photoelectric Effect: Optocoupler
2.14.1.4 Internal Photo Effect: Photovoltaic Effect
2.14.1.5 Photoionization
2.14.2 Photoelectric Sensor Elements
2.14.3 Photoelectric Sensor Elements
2.14.3.1 Photomultiplier
2.14.3.2 Optocoupler
2.14.3.3 Light Barriers
2.14.3.4 Photoelectric Switches
2.14.3.5 Light Curtain
2.14.3.6 Light Measurement
2.14.3.7 Colour Recognition
2.15 Electro-optical Effect
2.15.1 Principle of Operation and Physical Description
2.15.2 Materials
2.15.3 Applications
2.16 Electrochemical Effects
2.16.1 Principle of Operation and Classification
2.16.2 Potentiometric Sensors
2.16.3 Amperometric Sensors
2.16.4 Conductometric and Impedimetric Sensors
2.16.5 Areas of Application
2.17 Chemical Effects
2.17.1 Physical-chemical Interactions of Gases with Surfaces
2.17.2 Gas Solubility (Absorption)
2.17.3 Gas Transport to the Solid Surface
2.17.4 Adsorption and Chemisorption
2.17.5 Reactions with Adsorbed Species
2.17.6 Reaction of the Gas with the Solid
2.17.7 The Mixed-phase Disorder
2.18 Acoustic Effects
2.18.1 Definition and Classification of Sound
2.18.2 Characterization of Acoustic Waves
2.18.3 Sound Velocity in Ideal Gases
2.18.3.1 Dependence on Temperature
2.18.3.2 Dependence on the Relative Air Humidity
2.18.3.3 Dependence on Pressure
2.18.4 Intensity or Sound Intensity
2.18.5 Sound Absorption in Air
2.18.6 Reflection and Transmission
2.19 Optical Effects
2.19.1 Physical Effects
2.19.2 Design of Optical Sensors
2.19.3 Categories of Optical Sensors
2.19.4 Application Fields of Optical Sensors
2.20 Doppler Effect
2.20.1 Principle of Operation and Physical Description
2.20.1.1 Observer Moves, Source Rests
2.20.1.2 Source Moves, Observer Rests
2.20.1.3 Observer and Source Move
2.20.1.4 Doppler Effect of Light (Doppler Effect Without Medium)
2.20.2 Application Areas
2.20.2.1 Astronomy
2.20.2.2 Geodesy (Land Surveying)
2.20.2.3 Navigation
2.20.2.4 Vibration Analysis
2.20.2.5 Speed Measurement
2.20.2.6 Determination of Chemical Elements
2.20.2.7 Medical Technology
2.20.2.8 Acoustics
Bibliography
3: Geometric Quantities
3.1 Displacement and Distance Sensors
3.1.1 Inductive Distance and Displacement Sensors
3.1.1.1 Functional Principle and Morphological Description of Inductive Sensors
3.1.1.2 Non-contact Inductive Distance Sensors (INS)
Sensor Element and Block Diagram of the INS
Measuring Principle of the INS
Functionality and Sensor Electronics of the INS
Calibration of the INS
Applications and Main Characteristics of the INS
3.1.1.3 Non-contact Inductive Displacement Sensors (IWS)
Measuring Principle of the IWS
Sensor Element and Block Diagram of the IWS
Sensor Electronics and Realization of the IWS
Characteristics and Applications of the IWS
3.1.1.4 Differential Transformers with Sliding Core (LVDT)
Sensor Element and Measuring Principle of LVDTs
Functionality and Block Diagram of the LVDTs
Implementation of the LVDTs
Applications and Main Characteristics of LVDTs
3.1.1.5 Pulsed Inductive Linear Position Sensor (Micropulse BIW)
Sensor Element and Measuring Principle of the BIWs
Functionality and Block Diagram of the BIWs
Realization of the BIWs
Applications and Main Characteristics of the BIWs
3.1.1.6 Signal Processing by Phase Measurement (Sagentia)
Functionality
Actual Value Acquisition at a Hydraulic Steering Cylinder for Fork Lift Trucks
3.1.1.7 PLCD Displacement Sensors (Permanent Linear Contactless Displacement Sensor)
Sensor Element and Measuring Principle of PLCDs
Functionality and Block Diagram of the PLCDs
Realization
Applications and Characteristics
3.1.1.8 Non-contact Magnetoinductive Displacement Sensors (Smartsens-BIL)
Sensor Element and Measuring Principle of BIL Sensors
Function and Block Diagram of the BIL Displacement Sensor
Realization
Applications
BIL Main Characteristics
3.1.2 Optoelectronic Distance and Displacement Sensors
3.1.2.1 Overview
3.1.2.2 Optoelectronic Components
3.1.2.3 Optical Principles of Distance Sensors
Useful Signal
Contamination Indicator
Beam Path
Influence of the Condition of the Object Surface
Grey Value Shift
3.1.2.4 Measuring Principle: Triangulation
3.1.2.5 Measuring Principle: Pulse Delay Method
3.1.2.6 Measuring Principle: Phase or Frequency Delay Method
3.1.2.7 Measuring Principle: Photoelectric Scanning
3.1.2.8 Measuring Principle: Interferometric Length Measurement
3.1.3 Ultrasonic sensors for Distance Measurement and Object Detection
3.1.3.1 Operating Principles and Design Touch Operation with Echo Runtime Measurement
Barrier Operation
3.1.3.2 Design of the Ultrasonic Transducer
3.1.3.3 Detection Range of an Ultrasonic Sensor
3.1.3.4 Deflection of the Ultrasound
3.1.3.5 Object and Environmental Influences
Object Influences
Environmental Influences
3.1.3.6 Applications
3.1.4 Potentiometric Displacement and Angle Sensors
3.1.4.1 Introduction
3.1.4.2 Operating Principle and Characteristics of Potentiometric Sensors
Linearity Error
Resolution and Hysteresis
Temperature Coefficient
3.1.4.3 Technology and Construction Techniques
Wire Potentiometer
Cermet Layer System
Polymer Coating Systems
Layer Structure and Linearization
Grinder Systems
Foil Potentiometer
3.1.4.4 Products and Applications
Applications in Automotive Engineering
Industrial Applications
3.1.5 Magnetostrictive Displacement Sensors
3.1.5.1 Operating Principle and Design of Magnetostrictive Displacement Sensors
3.1.5.2 Housing Concepts and Applications
Profile Types
Rod Designs
Explosion-Proof Versions
Redundantly Designed Sensors for Safety Applications
Multiple Positions: One Sensor
Position-Controlled Hydraulic Drive
Control of the Angle of Attack in Fluid Mechanics
Conclusion
3.1.6 Displacement Sensors with Magnetically Coded Measuring Standard
3.1.6.1 Measuring Principle
3.1.6.2 Design and Function of Incremental and Absolute Measuring Systems
Incremental Magnetic Measuring Systems
Absolute Magnetic Measuring Systems
3.1.6.3 Characteristic Values
Linearity Deviation
Hysteresis
Following Error
3.1.6.4 Sensor Types in Comparison
3.1.6.5 Application Examples
3.2 Sensors for Angle and Rotation
3.2.1 Optical Encoders
3.2.1.1 Physical Principles
Rotary Encoder with Imaging Optics
Encoder Using the Moiré Effect
Encoder with Diffractive Optics
3.2.1.2 Design of Optical Encoders
Order
Light Source
Code Disk
Recipient
3.2.1.3 Special Features of Optical Encoders
Conditions of Use
Non-linearity
General Mechanical Engineering and Automation Technology
Lifetime
3.2.2 Magnetically Encoded Rotary Encoder
3.2.2.1 Applications
3.2.3 Rotation-Counting Angle Sensors
3.2.3.1 General Principle of Operation and Morphological Description of Rotation-Counting Angle Sensors
3.2.3.2 Gearbox-Based Revolution-Counting Methods
3.2.3.3 Rotation-Counting Method on Inductive Basis
3.2.3.4 Battery Buffering of the Rotation Information
3.2.3.5 Novel GMR System for Detection and Storage of Rotation Information
Sensor Element and Measuring Principle of the GMR Revolution Counter
Applications and Characteristics of the GMR Revolution Counter
Compact Solution for Many Applications
Characteristics of the GMR Revolution Counter Using the Example of the Version in the RSM2800 Series
3.2.4 Capacitive Encoders
3.2.5 Variable Transformers, Resolvers
3.2.5.1 General Operating Principle of the VT
3.2.5.2 Significant Variants of VT
3.2.5.3 Resolver, a Representative Variant of VT
3.2.6 1Vpp or Sin/Cos Interface
3.2.7 Incremental Encoders
3.2.7.1 Summary of the Properties of Incremental Interfaces
3.3 Inclination
3.3.1 Magnetoresistive Inclination Sensors
3.3.2 Compass Sensors
3.3.3 Electrolytic Sensors
3.3.4 Piezoresistive Inclination Sensors/DMS Bending Beam Sensors
3.3.5 MEMS
3.3.6 Servo-Inclinometer
3.3.7 Overview and Selection of Inclination Sensors
3.4 Sensors for Object Detection
3.4.1 Proximity Switch
3.4.1.1 Block Diagram of the NS, Detection Type and Mode of Operation of the NS
3.4.1.2 Main Features of the NS
3.4.1.3 Switching Distances
3.4.1.4 Hysteresis
3.4.1.5 Switching Element Function
3.4.1.6 Output Type
3.4.1.7 Design and Size
3.4.1.8 Characteristics of the NS
3.4.1.9 Special Designs and Their Applications
3.4.1.10 NS with Several Switching Outputs
3.4.1.11 NS with Diagnostic Information
3.4.1.12 Applications of the NS
3.4.2 Object Detection and Distance Measurement with Ultrasound
3.4.2.1 Speed of Sound in Air
3.4.3 Object Detection with Radar
3.4.3.1 Impulse Radar
3.4.3.2 CW Radar
3.4.3.3 Application
3.4.4 Pyroelectric Sensors for Motion and Presence Detection
3.4.4.1 Material Properties of Sputtered PZT Films
3.4.4.2 Effect on Electronics
3.4.5 Object Detection with Laser Scanner
3.4.5.1 Application
3.4.6 Sensors for Automatic Identification (Auto-Ident)
3.4.6.1 Overview
3.4.6.2 Barcode Scanner
Classification of Barcode Readers
Applications of Permanently Mounted Barcode Scanners
Structure and Function Modules of a Barcode Scanner
Nominal Reading Distance and Depth of Field of a Bar Code Scanner
Important Terms for Optimal Scanner Alignment
3.4.6.3 Auto-Ident Cameras
3.4.6.4 Construction of Auto-Ident Cameras
3.4.6.5 Important Fields of Application for Auto-Ident Cameras
3.4.6.6 RFID Systems and Readers
Categorization of the Tags
RFID Frequency Ranges
High Frequencies (HF, Mostly 13.56 MHz)
Very High Frequencies (UHF, 850 MHz to 950 MHz (e.g. According to EPC: Electronic Product Code))
Features and Examples of HF RFID Readers
Features and Applications of UHF RFID Readers
3.5 Three-Dimensional Measuring Methods (3D Measurement)
3.5.1 Palpable 3D Measurement Methods.
3.5.1.1 Switching Sensor
3.5.1.2 2-phase Switching Sensor
3.5.2 Optical Probing 3D Measuring Methods
3.5.2.1 Optical, Switching Single Point Sensor
3.5.2.2 Scanning Sensors
3.5.2.3 Other Probe and Measuring Systems
3.5.3 3D Imaging Measuring Methods
3.5.3.1 Optical 3D Measurement (Grid and Line Projection)
3.5.3.2 Measuring Principle and Measuring Arrangement
3.5.3.3 Fringe Projection
3.5.3.4 Limitations of the Procedure
3.5.3.5 Fields of Application
3.5.4 Overview of 3D Measuring Methods
Bibliography
4: Mechanical Measured Variables
4.1 Mass
4.1.1 Definition
4.1.2 Applications
4.2 Force
4.2.1 Definition
4.2.1.1 Weight Force FW
4.2.1.2 Centripetal Force Fcp
4.2.1.3 Elastic Force or Spring Force Fel
4.2.1.4 Frictional Force FF
4.2.2 Effects for the Applications
4.2.2.1 Piezoelectric Effect
Piezoresistive Effect
Electromagnetic Force Effect
Resonant Circuit
4.2.3 Application Areas
4.2.3.1 Process Control
Measuring Equipment Monitoring
Traffic Engineering
Medical Technology and Biomechanics
4.3 Elongation
4.3.1 Definition
4.3.2 Strain Measurement
4.3.2.1 Bending Beam
4.3.2.2 Fiber Bragg Grating
4.4 Pressure
4.4.1 Definition
4.4.1.1 Fields of Application
4.4.2 Measuring Principles
4.4.2.1 Measuring Principles
4.4.2.2 Differential Pressure Measurement
4.4.2.3 Relative Pressure Measurement
4.4.2.4 Absolute Pressure Measurement
4.4.3 Measuring Arrangements
4.5 Torque
4.5.1 Definition
4.5.2 Measuring Principles
4.5.3 Application Areas
4.6 Hardness
4.6.1 Definition
4.6.2 Macroscopic Hardness Determination
4.6.3 Hardness Determination by Nanoindentation
4.6.4 Sensors for Nanohardness Measurement
4.6.5 Model and Evaluation
4.6.6 Applications
5: Time-Based Measurements
5.1 Time
5.1.1 Definition
5.1.2 Measuring Principles
5.2 Frequency
5.2.1 Definition
5.2.2 Measuring Principles
5.2.3 Measuring Arrangements for Frequency and Time Measurement
5.2.4 Measurement Error of Time-Discrete Measurements
5.2.5 Measuring Arrangements
5.3 Pulse Width
5.3.1 Definition
5.3.2 Measuring Principles
5.3.3 Analogue Evaluation
5.3.4 Digital Evaluation
5.3.5 Measuring Arrangements
5.4 Phase, Running Time, and Light Running Time
5.4.1 Definition
5.4.2 Measuring Principles
5.4.3 Measuring Arrangements
5.4.4 Light Running Time
5.4.5 Direct Time-of-Flight Measurement
5.4.6 Transit Time Measurement Through Pulse Integration
5.4.7 Time of Flight Measurement with Modulated Light
5.5 Visual Representation of Measured Variables
5.5.1 Measuring Principle
5.5.2 Analogue Oscillographs
5.5.3 Digital Storage Oscilloscopes (DSOs)
5.5.4 Mixed Signal Oscilloscopes (MSOs)
5.5.5 The Sampling Principle
5.5.6 Measuring Arrangements
5.5.7 Voltage and Period Duration Measurement
5.5.8 Measurement of Rise Times
5.5.9 Measurement of Phases
5.5.10 Measurement of Pulse Duration and Pulse Ratios (PWM)
5.6 Speed and Angle of Rotation
5.6.1 Definition
5.6.2 Measuring Principles
5.6.3 Measurement Through Event Recording
5.6.4 Measurement by Position Detection
5.6.5 Speed Determination by Beating (Stroboscope)
5.6.6 Measuring Arrangements
5.6.6.1 Magnetic and Optical Scanning
5.6.7 Digital or A/B Interface (Incremental Encoder)
5.7 Speed
5.7.1 Definition
5.7.2 Measuring Principle Speed
5.7.3 Measuring Arrangements for Speed Measurement
5.8 Acceleration
5.8.1 Definition
5.8.2 Fields of Application
5.8.3 Measuring Principle Linear Acceleration
5.8.4 Measuring Principle Angular Acceleration
5.8.5 Measuring Arrangement for Measuring Acceleration
5.9 Flow Rate (Mass and Volume)
5.9.1 Definition
5.9.2 Mass
5.9.3 Volume
5.9.4 Volume Flow
5.9.5 Mass Flow
5.9.6 Main Groups
5.9.7 Measurement Methods and Application
5.9.8 Bulk Flow Meter
5.9.9 Baffle Plate Scales
5.9.10 Weighfeeders
5.9.11 Belt Scales
5.9.12 Differential Scales
5.9.13 Optical Belt Weigher
Bibliography
6: Temperature Measurement
6.1 Temperature as Physical State Variable
6.2 Measuring Principles and Measuring Ranges
6.3 Temperature Dependence of the Electrical Resistance
6.3.1 Metals
6.3.2 Metals with Defined Additives (Alloys) or Lattice Defects
6.3.3 Ion Conducting Materials for High Temperatures
6.3.4 Thermistors
6.3.5 Constriction Resistor Temperature Sensors (Spreading Resistor)
6.3.6 Diodes
6.4 Thermoelectricity (Seebeck Effect)
6.4.1 Thermocouples for Very High Application Temperatures
6.4.2 Metallic Thermocouples for Very High Application Temperatures
6.4.3 Inorganic-Non-metallic Thermocouples for Very High Application Temperatures
6.5 Thermal Expansion
6.5.1 Thermal Expansion of Solid Bodies
6.5.2 Thermal Expansion of Liquids
6.5.3 Thermal Expansion of Gases
6.6 Temperature and Frequency
6.7 Thermochromism
6.8 Seger Cone
6.9 Non-contact Optical Temperature Measurement
6.9.1 Radiation Thermometer (Pyrometer)
6.9.2 Fiber Optic Applications
6.9.2.1 Intrinsic Sensors, DTS (Distributed Temperature Sensing)
6.9.2.2 Extrinsic Sensors
Bibliography
7: Electrical and Magnetic Measured Variables
7.1 Voltage
7.1.1 Definition
7.1.1.1 AC Voltage
7.1.1.2 Measuring Principles
7.1.1.3 Conversion into an Electromagnetic Field
7.1.1.4 Conversion to Heat
7.1.1.5 Conversion into a Current
7.1.1.6 Measurement by Comparison with a Standard
7.1.2 Measuring Arrangements
7.1.2.1 Measurement by Energy Extraction
7.1.2.2 Measurement Through Integration
7.1.2.3 Measurement by Comparison
7.1.2.4 Servo Converter
7.1.2.5 The Successive Approximation
7.1.2.6 Measurement of Alternating Voltages
7.2 Amperage
7.2.1 Definition
7.2.1.1 Measuring Principles
7.2.1.2 Current Flow Through a Resistor
7.2.1.3 Thermal Effect of Current Flow
7.2.1.4 Magnetic Field Due to Current Flow
7.2.2 Measuring Arrangements
7.3 Electrical Charge and Capacity
7.3.1 Definition
7.3.1.1 Measuring Principle Charge
7.3.1.2 Measuring Principle Capacity
7.3.2 Measuring Arrangements
7.3.2.1 Capacity Measurement Through Charge Sharing
7.3.2.2 Capacity Measurement by RC Generators
7.3.2.3 Complex Components for Capacitance Determination
7.4 Electrical Conductivity and Specific Electrical Resistance
7.4.1 Definition
7.4.1.1 Measuring Principles for Resistance
7.4.2 Measuring Arrangements
7.4.2.1 Determination of Current and Voltage at the Measured Object
7.4.2.2 Resistance Measurement Through Compensation
7.4.2.3 AC Voltage Resistance Measurement
7.5 Electric Field Strength
7.5.1 Definition
7.5.2 Measuring Principles for the Electric Field Strength
7.6 Electrical Energy and Power
7.6.1 Definitions
7.6.1.1 Practical Case Accumulator
7.6.2 Forms of Power
7.6.2.1 Power in DC Circuit
7.6.2.2 Power in AC Circuit
7.6.3 Measuring Principles
7.6.3.1 Electromechanical
7.6.3.2 With Analogue Electronics
7.6.3.3 With Digital Electronics
7.6.3.4 With Statistical Methods
7.7 Inductance
7.7.1 Definition
7.7.2 Measuring Principles
7.8 Magnetic Field Strength
7.8.1 Definition
7.8.2 Measuring Principles of Magnetic Quantities
7.8.2.1 Hall Sensor
7.8.2.2 GMR Sensor
7.8.2.3 Field Plate
7.8.2.4 SQUID
7.8.3 Measuring Arrangements
7.8.3.1 Hall Switch
7.8.3.2 Hall Sensors
7.8.3.3 Angle Sensors
7.8.3.4 Current Sensors
7.8.4 Multidimensional Measurements with the Hall Effect
7.8.4.1 Basics
7.8.4.2 Applications
Bibliography
8: Radio and Photometric Quantities
8.1 Radiometry
8.1.1 Radiometric Quantities
8.1.1.1 Energy Density
8.1.1.2 Radiant Power
8.1.1.3 Solid Angle Omega
8.1.1.4 Radiant Intensity Ie
8.1.1.5 Radiance Le
8.1.2 Measurement of Electromagnetic Radiation
8.2 Photometry
8.2.1 Photometric Quantities
8.2.1.1 Luminous Flux V
8.2.1.2 Light Quantity Qv
8.2.1.3 Luminous Intensity Iv
8.2.1.4 Luminance Lv
8.2.1.5 Illuminance Ev
8.2.1.6 Specific Light Emission Mv
8.2.1.7 Luminous Efficacy η
8.2.2 Measurement of Photometric Quantities
8.3 Application of Brightness Sensors
8.4 Colour
8.4.1 Colour Perception
8.4.2 Colour Models
8.4.2.1 Other Color Spaces
8.4.3 Color Systems
8.4.4 Colour Filters for Sensors
8.4.4.1 Bayer Pattern
8.4.4.2 Color Correction
8.4.4.3 White Balance
8.4.5 Colour Sensors
Bibliography
9: Acoustic Measured Variables
9.1 Definition of Important Acoustic Quantities
9.2 Human Perception
9.2.1 Level
9.2.2 Volume
9.2.3 Loudness
9.3 Transducer
9.4 Fields of Application
Bibliography
10: Climatic and Meteorological Measured Variables
10.1 Moisture in Gases
10.1.1 Definitions and Equations
10.1.1.1 Humidity
10.1.1.2 Water Vapour Partial Pressure
10.1.1.3 Absolute and Specific Humidity
10.1.1.4 Saturation Humidity
10.1.1.5 Relative Humidity φ
10.1.1.6 Dew Point
10.1.1.7 Enthalpy
10.1.1.8 Mollier Diagram (h-x Diagram)
10.1.2 Humidity Measurements in Gases
10.1.2.1 Psychrometers, Design and Function
10.1.2.2 Design Types and Areas of Application
10.1.2.3 Aspiration Psychrometer
10.1.2.4 Slingshot Psychrometer
10.1.2.5 Dew Point Mirror
Functionality
Construction of the Dew Point Mirror
Hair Hygrometer
10.1.2.6 Capacitive Humidity Measurement
10.1.2.7 Integrated Capacitive Humidity Sensors with Bus Output
10.2 Moisture Analysis in Solid and Liquid Substances
10.2.1 Direct Methods for the Determination of Material Moisture
10.2.1.1 Percentage Water Content of a Material Sample
Technical Design for the Determination of the Gravimetric Water Content
10.2.1.2 Water Activity of a Material Sample
10.2.1.3 Karl Fischer Titration
10.2.1.4 Calcium Carbide Method
10.2.1.5 Calcium Hydride Method
10.2.2 Indirect Measuring Methods for Determining the Moisture Content of Materials
10.2.2.1 Measurement of the Electrical Properties
10.2.2.2 Detection of the Optical Properties of Water and Water Vapour
10.2.2.3 Measurement of the Suction Pressure in Moist Materials (Tensiometry)
10.2.2.4 Measurement of Atomic Properties
10.2.2.5 Nuclear Magnetic Resonance (NMR) Method
10.2.2.6 Measurement of Thermal Conductivity
10.3 Measurement of Precipitation in Outdoor Climate
10.3.1 Measurement of the Relative Air Humidity
10.3.2 Precipitation Measurement
10.3.3 Condensation Measurement
10.4 Humidity Measurement in Closed Rooms
10.4.1 Measurement of the Climate in Homes and at Workplaces
10.4.2 Climate in Museums and Exhibition Rooms
10.4.3 Climate in Electrical Installations
10.4.4 Influencing the Indoor Climate
10.4.4.1 Air Humidification
10.4.4.2 Evaporator
10.4.4.3 Steam Humidifier
10.4.4.4 Nebulizer
10.4.4.5 Dehumidifying Rooms
10.4.4.6 Condensation Dehumidification
10.4.4.7 Adsorption Dehumidifier
10.4.4.8 Absorption Dehumidifier
10.5 Air Pressure
10.5.1 Fields of Application
10.5.2 Measuring Principles
10.5.3 Definitions
10.6 Wind and Air Flow
10.6.1 Definition
10.6.2 Methods for Wind Measurement
10.7 Water Flow
10.7.1 Definition
10.7.2 Direct and Indirect Flow Measurement
10.7.2.1 Ultrasonic Measurement
10.7.2.2 Term Principle
10.7.2.3 Doppler Principle
10.7.2.4 Electromagnetic Measuring Method
10.7.2.5 Hydrometric Measuring Blade
10.7.2.6 Measurement with Markers (Tracers)
Bibliography
11: Selected Chemical Parameters
11.1 Redox Potential
11.1.1 General
11.1.2 Precious Metal Redox Electrodes
11.1.3 Redox Glass Electrodes
11.1.4 Reference Electrodes
11.2 Ions Including Hydronium Ions
11.2.1 General Information
11.2.2 pH Measurement
11.2.3 Other Ions
11.3 Gases
11.3.1 General Information
11.3.2 Gases in a Physically Dissolved State or at Normal Temperature
11.3.2.1 Solid Electrolyte Sensors
Classification and Meaning
Electrochemical Cells with Solid Electrolytes
Potentiometric Oxygen Measurement
Oxygen in Exhaust Gases
Lambda Sensor
Determination of the Redox Potential of Gases
Measurement of Oxygen in Liquid Metals
Current Carrying Solid Electrolyte Gas Sensors
Amperometric Solid Electrolyte Gas Sensors
Coulometric Determination of Oxygen
11.3.3 Semiconductor Gas Sensors: Metal Oxide Semiconductor Sensors (MOS)
11.3.3.1 Surface Conductivity
11.3.3.2 Volume Conductivity
11.3.4 Pellistors
11.4 Electrolytic Conductivity
11.4.1 General Information
11.4.2 Kohlrausch Measuring Cells
11.4.3 Multi-Electrode Measuring Cells
11.4.4 Electrodeless Conductivity Measuring Cells
11.4.5 Examples for the Application of Conductivity Sensors
12: Biological and Medical Sensors
12.1 Biological Sensor Technology
12.1.1 Biosensor Technology
12.1.2 Real Biological Sensors
12.2 Functional Principles of Biosensors
12.2.1 Calorimetric Sensors
12.2.2 Microgravimetric Sensors
12.2.3 Optical Sensors
12.2.4 Electrochemical Sensors
12.2.5 Immobilization Methods
12.3 Physical and Chemical Sensors in Medicine
12.3.1 Physical-Chemical Blood Analyses
12.3.2 Clinical-Chemical Blood Analyses
12.4 Enzymatic Methods: Enzyme Sensors
12.4.1 Enzyme-Based Analyte Detection
12.4.2 Determination of Enzyme Activity
12.4.3 Application Fields of Enzymatic Tests
12.5 Immunological Methods: Immunosensors
12.5.1 Direct Immunosensors
12.5.2 Indirect Immunosensors
12.5.3 Application Fields of Immunosensors
12.6 DNA-Based Sensors
12.6.1 Hybridization Diagnostics
12.6.2 Application and Use of DNA Sensors
12.7 Cell-Based Sensor Technology
12.7.1 Metabolic Cell Chip
12.7.2 Neuro-chip
Bibliography
13: Measured Quantities for Ionizing Radiation
13.1 Introduction and Physical Quantities
13.2 Interaction of Ionising Radiation with Matter
13.3 Classification of Sensors
13.4 Gas-Filled Radiation Sensors
13.5 Radiation Sensors According to the Excitation Principle
13.6 Semiconductor Sensors
Bibliography
14: Photoelectric Sensors
14.1 Radiation
14.2 Scintillators
14.3 Outer Photoelectric Effect
14.3.1 Photomultiplier
14.3.2 Channel Photomultiplier
14.3.3 Image Pickup Tubes
14.4 Internal Photoelectric Effect
14.4.1 Photoconductor
14.4.2 Photodiodes
14.4.3 Phototransistor, Photothyristor and Photo-FET
14.4.4 CMOS Image Sensors
14.4.5 High Dynamic CMOS Image Sensors
14.5 CCD Sensors
14.5.1 Line Sensors
14.5.2 CCD Matrix Sensors
14.6 Quantum Well Infrared Photodetector QWIP
14.7 Thermal Optical Detectors
14.7.1 Thermal Piles
14.7.2 Pyroelectric Detectors
14.7.3 Bolometer
15: Signal Processing and Calibration
15.1 Signal Processing
15.1.1 Analog (Discrete) Signal Conditioning
15.1.2 Signal Conditioning with System Circuits
15.1.3 Signal Conditioning with ASICs
15.1.4 Signal Conditioning with Microcontrollers
15.2 Sensor Calibration
15.2.1 Passive Compensation
15.2.2 Adjustment with Analog Signal Processing
15.2.3 Adjustment with Digital Signal Processing
15.3 Energy Management for Sensors
Bibliography
16: Interface
16.1 Analogue Interfaces
16.1.1 Voltage Output
16.1.2 Ratiometric Voltage Output
16.1.3 Current Output
16.1.4 Frequency Output and Pulse Width Modulation
16.1.5 4-/6-Wire Interface
16.2 Digital Interfaces
16.2.1 CAN Group
16.2.2 LON
16.2.3 HART
16.2.4 RS485
16.2.5 IO-Link
16.2.6 Profibus
16.2.7 I2C
16.2.8 SPI
16.2.9 IEEE 1451
Bibliography
17: Safety Aspects for Sensors
17.1 Features for Function Monitoring
17.2 Electromagnetic Compatibility (EMC)
17.3 Functional Safety (SIL)
17.4 Sensors in Explosive Environments (ATEX)
17.4.1 Basic Principles of ATEX
17.4.2 Ignition Protection Type Intrinsic Safety
17.4.3 Type of Protection Flameproof Enclosure
Bibliography
18: Measurement Errors, Measurement Accuracy and Measurement Parameters
18.1 Classification of Measurement Errors According to Their Cause
18.2 Display of Measurement Errors
18.2.1 Arithmetic Mean, Error Sum and Standard Deviation
18.2.2 Absolute Error
18.2.3 Relative Error
18.3 Measurement Parameters
18.3.1 Scattering of Measured Values
18.3.2 Resolution of Measured Values
18.3.3 Signal-to-Noise Ratio and Dynamics of Measured Values
Bibliography
Index