Industrial Instrumentation ppt1
Industrial Instrumentation ppt1
Industrial Instrumentation ppt1
BHARUCH
SUBJECT :
INDUSTRIAL
INSTRUMENTATION
1
PREPARED BY
NAMES ENROLLNMENT NO
Sarvaiya Mihir 140143109019
Rajput Rahul 140143109016
Pandor Nitin 120140109125
Pandya jayesh 140143109012
Gujar purvi 140143109003
Khatri hiren 140143109008
Pancholi dharti 140143109011
Trivedi harsh 140143109024
Solanki satish 130140109110
Zala kanji 130140109124
Parmar kanak 130140109056
Transducers
3
Terminology
Transducers convert one form of energy into another
Sensors/Actuators are input/output transducers
Sensors can be passive (e.g. change in resistance) or active
(output is a voltage or current level)
Sensors can be analog (e.g. thermocouples) or digital (e.g.
digital tachometer)
Sensor Actuator
4
Transducer types
Quantity being Input Device Output Device
Measured (Sensor) (Actuator)
Light Dependant Resistor (LDR), Lights & Lamps, LED's &
Light Level
Photodiode, Phototransistor, Solar Cell Displays, Fiber Optics
Thermocouple, Thermistor, Thermostat,
Temperature Heater, Fan, Peltier Elements
Resistive temperature detectors (RTD)
Lifts & Jacks, Electromagnetic,
Force/Pressure Strain Gauge, Pressure Switch, Load Cells
Vibration
Potentiometer, Encoders, Reflective/Slotted
Position Motor, Solenoid, Panel Meters
Opto-switch, LVDT
Tacho-generator, Reflective/Slotted Opto- AC and DC Motors, Stepper
Speed
coupler, Doppler Effect Sensors Motor, Brake
Sound Carbon Microphone, Piezo-electric Crystal Bell, Buzzer, Loudspeaker
5
Positional Sensors: potentiometer
Can be Linear or Rotational
Processing circuit
6
Positional Sensors: LVDT
Linear Variable
Differential
Transformer
7
Positional Sensors: Inductive Proximity Switch
Detects the presence of metallic objects (non-contact) via
changing inductance
Sensor has 4 main parts: field producing Oscillator via a
Coil; Detection Circuit which detects change in the field;
and Output Circuit generating a signal (NO or NC)
Used in traffic lights (inductive loop buried under the road). Sense
objects in dirty environment.
Does not work for non-metallic objects. Omni-directional.
8
Positional Sensors: Rotary Encoders
Incremental and absolute types
Incremental encoder needs a counter, loses absolute
position between power glitches, must be re-homed
Absolute encoders common in CD/DVD drives
9
Temperature Sensors
Bimetallic switch (electro-mechanical) used in
thermostats. Can be creep or snap action.
Creep-action: coil or spiral that unwinds or coils with changing
temperature
11
12
Light sensors: photoconductive cells
Light dependent resistor (LDR) cell
13
Light level sensitive switch
14
Photojunction devices
phototransistor
photodiode
15
Photovoltaic Solar Cells
Can convert about 20% of light power into electricity
Voltage is low (diode drop, ~0.6V)
16
Photomultiplier tubes (PMT)
Most sensitive of light sensors (can detect individual
photons)
Acts as a current source
electrons
17
Motion sensors/transducers
Switches, solenoids, relays, motors, etc.
Motors
DC
Brushed/brushless
Stepper motor
Servo
Stepper motors
AC
20
Summary
Weve only briefly touched on most basic types
Many other transducers are used/common, almost for any
physical quantity one can think of
Processing electronics is often essential: output of many
sensors is not linear, needs impedance transform, filtering,
etc.
For additional references see
http://www.electronics-tutorials.ws/io/io_1.html
Handbook of Transducers by H.N. Norton
http://www.sparkfun.com
21
THANK YOU
22