This presentation includes general types, basic components and working principle of Transparent/Clear object sensor. Also it includes advantages and disadvantages of both Photo-transistor based and ultra sonic based sensor.

1. Transparent/Clear
Object Sensor
(Glass Sensor)

2. Group Members
 Syed Atif Iqrar (332-FET/BSME/F13)
 Rashid Saeed (333-FET/BSME/F13)
 Muhammad Waleed (331-FET/BSME/F13)
Department of Mechanical Engineering, IIU Islamabad

3. Contents
 Introduction
 Transparent object Sensor
 Types of Transparent object Sensor
 Ultrasonic Sensor (Clear Object Sensor)
 Working Principle
 Ultrasonic sensor construction
 Characteristics & Considerations
 Advantages and Disadvantages
 Applications

4. Introduction
The World of Transparent Materials
Automation specialists have to find their way in the world of transparent materials
in many manufacturing processes.
 Clear plastic packaging
 bottles made of glass or PET, vials and dropper
 Flat, tube and hollow glass

5. Transparent Object Sensor
To handle various transparent materials in manufacturing industries as well as in
robotic industries Transparent Object Sensor are essential part of manufacturing
systems
A transparent object sensor is a photoelectric sensor which is used to detect
transparent objects at different ranges for different materials such as glass and
plastics of variety of shapes and structures in various manufacturing processes.

6. Types of Transparent Object Sensor
There are mainly three types of transparent object sensor
 Capacitive Sensor
 Optical Sensor
 Ultrasonic Sensor

7. Capacitive Sensor
(Clear Object Sensor)
 It works on the principle of changing value of relative permittivity for inserted
dielectric.
 There are two charged plates held in front of each other with air as dielectric. The
conveyer is placed in between the two plates on which the transparent object
must be passed.
 As the transparent object is passed, the value of relative permittivity of pre-
described dielectric is changed.
 By measuring how much value of relative permittivity is changed the material of
passed object can be found out.
 These sensors are used for counting number of objects or level of filled material
in transparent object could be determined in large scale production industries.

8. Working Principle
Material is transparent in our case

9. Optical Sensor
(Clear Object Sensor)
 These sensors are also known as photoelectric sensor.
 Photoelectric sensors provide non-contact accurate detection of targets.
 They emit infrared, red or laser light and the target breaks the light beam or
reflects the beam back to the sensor to activate the sensor output.
 Photoelectric sensing modes are divided into three primary
types, those being through-beam, retro-reflective
and diffuse.

10. Working Principle

11. Ultrasonic Sensor
(Clear Object Sensor)
 Ultrasonic sensors emit a sound pulse that reflects off objects entering
the wave field.
 The reflected sound, or “echo” is then received by the sensor. Detection of
the sound generates an output signal for use by an actuator, controller, or
computer.
 The output signal can be analogue or digital.
Figure:1.1

12. Working Principle
 Ultrasonic sensing technology is based on the principle that sound has a
relatively constant velocity.
 The time for an ultrasonic sensor’s beam to strike the target and return is
directly proportional to the distance to the object
 Ultrasonic sensors emit short bursts of high frequency sound waves.
 When the sound waves strike an object, an echo is reflected to the
ultrasonic sensor.
 The time it takes for the sound to travel to the object and back to the
sensor (time of flight) is measured and converted into a distance for reliable
detection in position and level applications.

13. Ultrasonic Sensor Construction
There are four basic components of an ultrasonic proximity sensor
 Transducer/receiver
 Comparator
 Detector circuit
 Solid-state output

14. Spacing Considerations
 spacing between sensors is determined by their beam angles.
 The sensors must be spaced so they do not interfere with each other.
 This interference is sometimes called “crosstalk.”

15. Target Considerations
 Generally, ultrasonic proximity sensors are affected less by target surface
characteristics
 however, they require the transducer face be within 3° of parallel to
smooth, flat target objects

16. Target Thermal state
 The surface temperature of a target can also influence the sensing range
 Radiated heat from high temperature targets distorts the sound beam
 Leading to shortened sensing range and inaccurate readings.

17. Target-to-Sensor Distance
 The further a target is away from the sensor
 the longer it takes the sensor to receive the echo.

18. Environmental Considerations
There are main four environmental considerations
 Ambient Noise
 Air Pressure
 Air Temperature
 Air Turbulence

19. Advantages & Disadvantages
Advantages:
 It’s response is not dependent upon the surface color or optical reflectivity of
the object. For example, the sensing of a clear glass plate, a brown pottery
plate, a white plastic plate, and a shiny aluminum plate is the same.
 Ultrasonic sensors with digital (ON/OFF) outputs have excellent repeat
sensing accuracy
 The response of analog ultrasonic sensors is linear with distance. By
interfacing the sensor to an LED display.
it is possible to have a visual indication of target distance. This makes ultrasonic
sensors ideal for level monitoring or linear motion monitoring applications.

20. Advantages & Disadvantages
Disadvantages:
 Ultrasonic sensors have a minimum sensing distance
 Changes in the environment ,such as temperature, pressure, humidity, air
turbulence effect ultrasonic response
 Targets of low density, like foam and cloth, tend to absorb sound energy;
these materials may be difficult to sense at long range.

21. Applications
Fill level monitoring PET bottle detection

22. Applications
Tray, Transparent Beaker detection Filled bottle detection

23. Applications
Inox, bottle detection in aggressive environment Transparent packaging material detection

24. Any Query?