a SENSOR OVERVIEW I Sensors: Convert a Signal or Stimulus - PowerPoint PPT Presentation

PRACTICAL DESIGN TECHNIQUES FOR SENSOR SIGNAL CONDITIONING I 1 Introduction 2 Bridge Circuits 3 Amplifiers for Signal Conditioning 4 Strain, Force, Pressure, and Flow Measurements 5 High Impedance Sensors 6 Position and Motion Sensors 7 Temperature Sensors 8 ADCs for Signal Conditioning 9 Smart Sensors 10 Hardware Design Techniques 1.0 a

SENSOR OVERVIEW I Sensors: Convert a Signal or Stimulus (Representing a Physical Property) into an Electrical Output I Transducers: Convert One Type of Energy into Another I The Terms are often Interchanged I Active Sensors Require an External Source of Excitation: RTDs, Strain-Gages I Passive (Self-Generating) Sensors do not: Thermocouples, Photodiodes 1.1 a

TYPICAL SENSORS AND THEIR OUTPUTS PROPERTY SENSOR ACTIVE/ OUTPUT PASSIVE Temperature Thermocouple Passive Voltage Silicon Active Voltage/Current RTD Active Resistance Thermistor Active Resistance Force / Strain Gage Active Resistance Pressure Piezoelectric Passive Voltage Acceleration Accelerometer Active Capacitance Position LVDT Active AC Voltage Light Intensity Photodiode Passive Current 1.2 a

TYPICAL INDUSTRIAL PROCESS CONTROL LOOP REMOTE CONTROL ROOM SIGNAL 4 TO 20mA 4 TO 20mA SIGNAL CONDITIONING TRANSMITTER RECEIVER CONDITIONING TEMP ADC SENSOR HOST MICRO PROCESS COMPUTER CONTROLLER HEATER DAC SIGNAL 4 TO 20mA 4 TO 20mA SIGNAL CONDITIONING RECEIVER TRANSMITTER CONDITIONING 1.3 a

STANDARDIZATION AT THE DIGITAL INTERFACE USING SMART SENSORS FIELD NETWORK BRANCH NODE NODE SMART SENSOR SMART SENSOR DEVICE NETWORK NODE SMART SENSOR SMART SENSORS OFFER: I Self-Calibration NODE I Linearization SMART SENSOR I Interchangeability I Standard Digital Interfaces 1.4 a

BASIC ELEMENTS IN A "SMART" SENSOR Pressure Sensor, RTD, Thermocouple, Strain Gage, etc. Precision Amplifier High Resolution ADC Microcontroller Sensor 1.5 a

THE EVEN SMARTER SENSOR Pressure Sensor, RTD, Thermocouple, Strain Gage, etc. MicroConverter TM ! Sensor 1.6 a