Sensors Handbook

There are many types of object detection sensors available on the industry market. Some of them, such as limit switches, require direct contact with the object.

Contents

Others, such as proximity sensors, need to be in close physical range but do not make contact with the object.

Still others can detect objects from much further distances; examples include photoelectric, laser and ultrasonic sensors.

This sensors handbook consists of 12 chapters as mentioned in the below table.

Chapter 1	Introduction to Different Types of Sensors
Chapter 2	Common Terms Used for Discrete Sensors
Chapter 3	What Type of Sensors Do I Need?
Chapter 4	Limit Switches
Chapter 5	Inductive Proximity Sensors
Chapter 6	Magnetic Proximity Sensors
Chapter 7	Capacitive Proximity Sensors
Chapter 8	Ultrasonic Proximity Sensors
Chapter 9	Photoelectric Sensors
Chapter 10	Special Sensors
Chapter 11	Sensors with Analog Output
Chapter 12	Conclusion

Limit Switches

Limit switches are one of the most common object detection sensors used in industrial controls. They are energized when an object makes physical contact with the actuator.

They normally provide an electro-mechanical contact closure, but some also move a pneumatic valve. There are many different form factors and actuator styles to choose from.

Inductive Proximity Sensors

Inductive proximity sensors detect the presence of metallic objects at close range (under 1.5 inches typically).

Ferrous metals allow the greatest distances to the sensor; other metals may reduce detection range.

Magnetic Proximity Sensors

Magnetic proximity sensors are used for non-contact object detection beyond the normal limits of inductive sensors.

Used with a separate damping magnet, they offer very long sensing ranges in a small package and can detect magnets through walls of non-ferrous metal, stainless steel, aluminum, plastic, or wood.

Capacitive Proximity Sensors

Capacitive proximity sensors use a dielectric plate generating an electrostatic field to detect both metal and non-metal objects and can sense through insulating materials such as wood or plastic.

They are often used to detect fill levels of liquids, pellets, and powders through container walls.

Capacitive sensors are available in cylindrical or rectangular shapes, with sensing distances typically up to 40mm.

Photoelectric Sensors

Photoelectric sensors use reflected or detected light waves to detect object presence or distance in a wide range of industrial applications.

They typically contain all required optics and electronics in a single unit, requiring only power to provide an output based on their specifications and object detection criteria.

Photoelectric sensors can detect a wide variety of materials and have extended sensing ranges.

Special Sensors

Other object detection sensors are available for specialized applications. Some specialty sensors available that work similarly to a photoelectric sensor are laser sensors, fiber optic sensors, fork sensors, and area sensors.

Although not seen as often as other types of sensors in the automation industry, they can be vital to an application with unique needs.

Title:	Practical Guide to Discrete Sensors for Industrial Applications
Author:	Automation Direct
Format:	PDF
Size:	2.3 MB
Pages:	36
Download:	Click Here