Industrial Automation and Control Chapter 1

1. CHAPTER-1
SENSORS
SUVENDU MONDAL
AP,EED,SURTECH
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2. DISPLACEMENT SESNOR
• Linear Potentiometer: A linear potentiometer is a type of
displacement sensor that measures linear movement. It consists of a
resistive element and a wiper that moves along the resistor as the
object being measured moves. As the wiper moves, it changes the
resistance, which is then measured to determine the displacement.
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3. DISPLACEMENT SESNOR
• LVDT (Linear Variable Differential Transformer):The LVDT is another
type of displacement sensor that measures linear movement. It
consists of a primary coil, two secondary coils, and a movable core. As
the object being measured moves, the core moves within the coils,
changing the inductance of the coils. This change in inductance is
then measured to determine the displacement.
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4. DISPLACEMENT SESNOR
• Capacitive Displacement Sensor: The capacitive displacement sensor
measures changes in capacitance to determine displacement. It
consists of two conductive plates separated by a dielectric material.
As the object being measured moves, it changes the distance
between the plates, which changes the capacitance. This change in
capacitance is then measured to determine the displacement.
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5. DISPLACEMENT SESNOR
• Eddy Current Displacement Sensor: The eddy current displacement
sensor uses electromagnetic induction to measure displacement. It
consists of a coil and a conductive target. As the target moves, it
induces eddy currents in the target, which then create a magnetic
field that is sensed by the coil. This change in magnetic field is then
measured to determine the displacement.
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6. Ultrasonic sensors
• Ultrasonic sensors are electronic devices that use sound waves to detect the
presence, distance, and other properties of objects. They work by emitting high-
frequency sound waves that bounce off nearby objects and return to the sensor.
By measuring the time it takes for the sound waves to travel to and from the
object, the sensor can determine the distance to the object.
• Ultrasonic sensors are commonly used in automation and robotics applications,
such as object detection, distance measurement, and position sensing. They can
also be used in medical equipment, automotive applications, and home security
systems.
• Ultrasonic sensors have some advantages over other types of sensors, such as
infrared or optical sensors. They can detect objects regardless of color or texture,
and they are less affected by ambient light. However, they may have difficulty
detecting objects with irregular shapes or surfaces, and their accuracy may be
affected by environmental factors such as temperature and humidity.
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7. Force Sensors
• Force sensors are electronic devices that measure the force applied to them. They convert the
physical force into an electrical signal that can be measured and analyzed. Force sensors can be
used to measure a wide range of forces, from small forces in the milli newton range to large
forces in the kilo newton range.
• There are different types of force sensors, including strain gauge sensors, piezoelectric sensors,
capacitive sensors, and magnetic sensors. Strain gauge sensors are the most common type of
force sensor and work by measuring the strain or deformation of a material under stress.
Piezoelectric sensors generate an electrical charge when they are subjected to mechanical stress,
while capacitive sensors measure changes in capacitance due to the applied force. Magnetic
sensors measure the changes in magnetic fields that are produced by the applied force.
• Force sensors have a wide range of applications in various fields, such as manufacturing, robotics,
medical equipment, and aerospace. They can be used to measure forces in machines, to monitor
the performance of engines, to measure the force exerted by a human hand or foot, and to
measure the forces involved in material testing.
• Overall, force sensors are essential tools for measuring forces accurately and reliably in various
applications, and they are continuously being improved to meet the ever-increasing demands of
industry and science.
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8. Temperature sensors
• Temperature sensors are electronic devices that measure temperature and convert it into an electrical signal that can be read and
analyzed. There are many types of temperature sensors, each with its own set of advantages and limitations.
• One of the most common types of temperature sensors is the thermocouple, which works by measuring the voltage generated
when two different metals are joined together and subjected to a temperature gradient. Another common type of temperature
sensor is the resistance temperature detector (RTD), which measures changes in electrical resistance in response to temperature
changes. Thermistors are another type of temperature sensor that work by measuring changes in electrical resistance in response
to temperature changes, but they have a different resistance-temperature characteristic compared to RTDs.
• In addition to these types of sensors, there are also infrared temperature sensors that work by measuring the amount of infrared
radiation emitted by an object, which can be used to determine its temperature without making physical contact. These sensors
are commonly used in industrial applications, where they can measure the temperature of objects that are too hot to touch or too
far away to reach.
• Temperature sensors have a wide range of applications in many fields, including manufacturing, automotive, aerospace, medical
equipment, and environmental monitoring. They are used to monitor and control temperature in various processes, to ensure
product quality, and to protect equipment from damage due to overheating.
• Overall, temperature sensors are essential tools for measuring temperature accurately and reliably in various applications, and
they play an important role in ensuring the safety, efficiency, and quality of many processes and products.
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9. Pressure sensors
• Pressure sensors are electronic devices that measure the pressure of gases or liquids and convert
it into an electrical signal that can be read and analyzed. They are used to measure different types
of pressure, such as absolute pressure, gauge pressure, and differential pressure.
• There are many types of pressure sensors, including piezo resistive sensors, capacitive sensors,
piezoelectric sensors, and resonant sensors. Piezo resistive sensors measure the changes in
electrical resistance that occur when a material is subjected to pressure. Capacitive sensors
measure changes in capacitance that occur due to changes in the distance between two
conductive plates. Piezoelectric sensors generate an electrical charge when subjected to
mechanical stress, while resonant sensors measure changes in the resonant frequency of a
vibrating element due to pressure changes.
• Pressure sensors are used in many different applications, including automotive, medical,
aerospace, and industrial applications. They are used to measure the pressure in engines, tires,
and hydraulic systems, to monitor blood pressure and other physiological parameters, to measure
the pressure in aircraft cabins, and to measure the level of liquids in tanks.
• Overall, pressure sensors are essential tools for measuring pressure accurately and reliably in
various applications, and they are continuously being improved to meet the ever-increasing
demands of industry and science.
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