This document discusses various sensors including smoke sensors, parking sensors, pedometers, pressure sensors, and accelerometers. It provides details on the types, working mechanisms, and applications of each sensor. Smoke sensors are discussed in depth including ionization, optical, and carbon monoxide types. Parking sensors use electromagnetic or ultrasonic sensors to alert drivers to obstacles. Pedometers count steps using mechanical or MEMS sensors. Pressure sensors include strain gauge, capacitive, and piezoelectric types and are used in industries like automotive and biomedical. Accelerometers measure acceleration using capacitive, piezoelectric, or piezoresistive mechanisms and have applications in devices, robots, and seismic monitoring.

1.  NITHYAPRIYA.S
 PRASHANNA
 PRAVEEN.S
 PREETHI.A

2. CONTENTS
Sensor
Types Of Sensor
Smoke Sensor
Parking Sensor
Pedometer
Pressure Sensor
Accelerometer

3. What is sensor?
An object that detects changes or events in the environment and produces
corresponding output
A type of transducer
Example: A thermometer
Mechanical
Temperature
Chemical
Optical
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4. Examples of sensors2

5. SMOKE DETECTOR
 A device that senses smoke typically as an indicator of fire
 Size-150 mm in diameter and 25 mm in thickness
 Ionisation
 Optical
 Projected beam
 Aspirating
 Carbonmonoxide
Types
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6. Working of optical smoke detector4

7. Working of ionisation smoke
detector
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8. Advantages
 Optical smoke detector contains no radioactive material
 Ionisation smoke detectors are cheaper than other types of smoke alarms
 Carbon monoxide alarms are used in addition to smoke alarms for increased
warning
 Needs regular checking and replacement of batteries
 Triggers false alarms when installed near steam rooms, stoves, toaster ovens
and high dust areas
 Optical smoke detectors are expensive
Disadvantages
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9. PARKING SENSOR
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10. INTRODUCTION
 Parking sensors are used for alert the driver to obstacles
while parking.
 These sensors use electromagnetic or ultrasonic sensors.
 The parking sensor is called as Reverse Aid which was
invented by Dr . Tony Heyes.
 After patenting the sensor , Heyes offered it to Jaguar cars.
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11. Electromagnetic System
 These sensor was invented by Mauro Del Signore In 1992.
 These sensors rely on the vehicle moving slowly and
smoothly towards the object to be avoided.
 These sensors are mounts on the inner side of the bumper.
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12. Ultrasonic Systems
 These systems feature ultrasonic proximity detectors to
measure the distances to nearby objects through sensors.
 Rear sensors are activated by selecting the reverse gear
and deactivated by selecting other gear.
 These system may not detect flat objects or large object to
reflect sound.
 These sensors are driven by intermittent waves called
Burst waves.
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13. PEDOMETER
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14. INTRODUCTION
 Pedometer is a sensor that is used to count the steps
taken by the person.
 They are becoming popular as an exercise counter and
motivator.
 These sensors are integrated into electronic devices.
 The first pedometer was developed by Abraham-Louis
Perrelet.
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15. TECHNOLOGY
 The technology includes a mechanical sensor and
software to count steps.
 Advanced step counters relay on MEMS interial sensors
and software to detect steps.
 Pedometer are accurate at flat surface.
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16. INTEGRATIONIN ELECTRONICDEVICES
 1. NIKE&iPod
 2. FITBIT.
 3. NTT DOCOMO FUJITSU PHONE.
 4. NOKIA 5500 SPORTS PHONE.
 5. SONY ERICSSON WALKMAN PHONE.
 6. APPLE PRODUCTS.
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17. PRESSURE
SENSORS15

18. TYPES OF PRESSURE
SENSOR
Absolute Pressure Sensor
Differential Pressure Sensor
Gauge Pressure Sensor
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19. TYPES OF PRESSURE SENSORS
Strain Gauge Type
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20. Capacitive Pressure Sensor
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21. Piezoelectric Pressure Sensor
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22. Applications of Pressure
Sensors
Touch Screen
Devices
Automotive Industry
Bio Medical
Instrumentation
Industrial Uses
Aviation
Marine Industry
Leak testing
Marine Industry
Pressure sensing
Altitude sensing
Flow sensing
Level / depth sensing
Ratiometric
Correction of
Transducer Output
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23. What is an Accelerometer?
 An accelerometer is an ELECTROMECHANICAL device
that measures acceleration ("g-force") forces which may
be STATIC, or they could be DYNAMIC.
 These are sensing transducers that provide an output
proportional to acceleration, vibration, and shock.
 Accelerometers are available that can measure
acceleration in one, two, or three orthogonal axes.
MODES OF USAGE
 For inertial measurement of velocity and position.
 As a inclination, tilt, or orientation sensor.
 As a vibration or shock sensor.
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24. Types and working of
Accelerometer
 Capacitive
 Piezoelectric
 Piezoresistive(electrical resistance)
 Heat transfer(changes in heat)
 Hall effect(change in magnetic field)
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25. Working of capacitive and
piezoelectric accelerometer
s.no capacitive piezoelectric
1. Output voltage depends on
the distance between two
planar surfaces.
Output voltage depends on the
pressure exerted on the crystal
2. Changing the gap between
the plates changes the
electrical capacity of the
system, which can be
measured as output.
Mass exerted over the crystal
may produce piezoelectric effect
due to which the voltage is
produced
adv high accuracy and stability. no need for electric supply to
sense, used to measure shock
disa
d
A Supply is needed Not used to measure g force
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26. Working of accelerometer chip in mobiles
 Below the red electrode, and separated from it by an air gap,
there's a second electrode (purple).
 The air gap between the two electrodes means the red and
purple electrodes work together as a capacitor.
 As you move the accelerometer and the red electrode moves
up and down, the distance between the red and purple
electrodes changes, and so does the capacitance between
them hence an equivalent voltage output is produced.
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27. Specifications
 Analog/digital
 Number of axes
 Output range (maximum swing)
 Sensitivity (voltage output per g)
 Dynamic range
 Mass
POTENTIAL APPLICATIONS
 To measure tilt angle.
 To sense movement.
 In laptops to protect hard drives from damage.
 Airbag deployment systems for modern automobiles.
 In self-balancing robots, auto pilot mode.
 physical therapy devices.
 In wireless gaming consoles and mobile phones.
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28. Recent applications.
 Air writing
 Pretouch
 In drones and other flying objects
 Seismometers-used to measure earthquakes
 And also to record earthquake
 To measure cable noise(produced due to
current flow).
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29. REFERENCE
 en.m.wikipedia.org
 www.sensormag.com
 www.engineersgarage.com
 www.first-sensor.com>pressure-types
 www.allsensors.com>applications
 http://www.sensorwiki.org/doku.php/sensors/accelerometer
 http://www.dimensionengineering.com/info/accelerometers
 http://www.explainthatstuff.com/accelerometers.html

30. THANK YOU
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