Sensors

1. Sensors Ananya, Sumika, Estif

2. Pressure sensors • A pressure sensor measures pressure, typically of gases or liquids. • Pressure sensors are used for control and monitoring in thousands of everyday applications. Pressure sensors can also be used to indirectly measure other variables such as fluid/gas flow, speed, water level, and altitude.

3. Pressure sensing This is where the measurement of interest is pressure, expressed as a force per unit area. This is useful in weather instrumentation, aircraft, automobiles, and any other machinery that has pressure functionality implemented. Altitude sensing This is useful in aircraft, rockets, satellites, weather balloons, and many other applications. All these applications make use of the relationship between changes in pressure relative to the altitude.

4. Advantages • It is very accurate while measuring the pressure of something • It is Adaptable to many applications

5. Limitations • They usually cost too expensive and can only be found in specialized shops. • Sensitive to slightest vibrations

6. Motion Sensors • A motion sensor is a device that detects moving objects, particularly people. • A motion detector is often integrated as a component of a system that automatically performs a task or alerts a user of motion in an area. • Motion detectors are commonly used as a component of security, automated lighting control, home control, energy efficiency, and other useful systems.

7. How It Works An electronic motion detector contains a motion sensor that transforms the detection of motion into an electric signal. This can be achieved by measuring optical changes in the field of view.

8. Uses Amusement park • Automatic control of devices (establishes timing for device start-up) Monitor camera • Detects the presence of a person and displays the image on the screen in the house Air conditioner • Detects the presence of a person and sends air

9. Advantages • Save energybecause it can automatically turn off the light and appliances when no one is in the room. • Easy to install

10. Limitations • Things may trigger the motion detector that you don't want to • The reliability of a motion sensor may also be affected by rapid environmental changes and direct sunlight.

11. Infrared sensors • An infrared sensor is an electronic device that emits and/or detects infrared radiation in order to sense some aspect of its surroundings. • Infrared sensors can measure the heat of an object, as well as detect motion. Many of these types of sensors only measure infrared radiation, rather than emitting it

12. How It Works • In a typical infrared sensor radiation enters the front and reaches the sensor itself at the center of the device. • This part may be composed of more than one individual sensor, each of them being made from pyroelectric materials, whether natural or artificial. • These are materials that generate an electrical voltage when heated or cooled.

13. These pyroelectric materials are integrated into a small circuit board. They are wired in such a way so that when the sensor detects an increase in the heat of a small part of its field of view, it will trigger the motion detector's alarm. • Pyroelectric:- Having the property of becoming electrically charged when heated.

14. Uses • It is used in motion sensors • Infrared detectors are commonly used in the construction of skyscrapers and large structures to detect leaks in pipes that otherwise would not have been possible to see.

15. Advantages • Many things are controlled by infrared. sensors are invisible to the naked eye • These sensors are very reliable. • An advantage of infrared detectors is their ability to be applied to a large area.

16. Limitations • Most infrared sensors must be lined up or they will not work. • Sometimes they cannot detect differences in objects that have a very similar temperature range. This leads to inaccuracy in many circumstances. • Infrared detectors are extremely expensive

17. Heat Sensors • A heat sensor is a device that measures temperature using lots of different ways . A heat sensor has two important elements which are the temperature sensor and some way of changing this physical change into a value. Heat sensors electronically makes a digital display or input to a computer.

18. How they Work • Objects emit infrared radiation which we can’t see with our naked eye. There are specialized equipment's that can observe the heat radiation. • The heat sensor’s collects and analyzes the heat by using pyroelectrical materials which emit electrical impulses when heated and cooled. • The electrical impulses is then collected and electronically turned into usable data.

19. Uses • Medical devices • Chemical handling • Weather stations • Army • Fire alarms

21. http://en.wikipedia.org/wiki/Motion_detector • http://motionsensortech.blogspot.in/2007/06/benefits-of-motion-sensor.html • http://wiki.answers.com/Q/Disadvantages_for_motion_sensor?#slide=9 • en.wikipedia.org/wiki/Pressure_sensor • http://www.wisegeek.org/what-is-an-infrared-sensor.htm • http://wiki.answers.com/Q/Advantages_and_disadvantages_of_infrared • http://www.ehow.com/facts_6151444_advantages-disadvantages-infrared-detectors.html • http://www.digikey.com/en-US/articles/techzone/2011/oct/temperature-sensors-the-basics • http://en.wikipedia.org/wiki/Heat_flux_sensor • http://www.ehow.com/how-does_4613395_heat-sensors-work.html?ref=Track2&utm_source=ask

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