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Classification methods & Classification - Inductive Proximity Sensors

Introduction &
Features

Classification
methods &
Classification

Precautions for
prorer use

Classification methods & Classification

Method of classification

(1) Classification by structure

This classification is based on whether the constituent circuit elements are built-in or separated. It is useful for selecting sensors in view of the mounting space, power supply, and noise immunity.

Inductive proximity sensor (High-frequency oscillation type)	Amplifier built-in
	Amplifier-separated

(2) Classification by coil enclosure

This classification is based on the structure surrounding the sensor head (detection coil). It is useful for selecting sensors in view of the mounting style, sensing range, influence of surroundings, etc.

Inductive proximity sensor (High-frequency oscillation type)	Shielded
	Non-shielded

(3) Classification by output circuit

This classification is based on the type of output circuit and the output voltage. This classification is useful to select sensors according to the input conditions of the device or equipment connected to the sensor output.

Inductive proximity sensor (High-frequency oscillation type)	ON / OFF output	NPN open-collector transistor
		PNP open-collector transistor
		DC 2-wire
	Analog output	Analog voltage
	Analog output	Analog current

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Classification

(1) Classification by structure

Type	Outline and Features
Amplifier built-in	As the amplifier is built-in, a non-contact output is obtained simply by connecting a DC electric power supply. It has high noise immunity because the amplifier is builtin.
Amplifier-separated	The sensing portion can be made small since the detection coil is separated as the sensor head. (However, its noise immunity is less than that of the amplifier built-in type.) The sensitivity setting can be done on the amplifier at a remote place.

Type

Outline and Features

Amplifier built-in

As the amplifier is built-in, a non-contact output is obtained simply by connecting a DC electric power supply.
It has high noise immunity because the amplifier is builtin.

Amplifier-separated

The sensing portion can be made small since the detection coil is separated as the sensor head.
(However, its noise immunity is less than that of the amplifier built-in type.)
The sensitivity setting can be done on the amplifier at a remote place.

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(2) Classification by coil enclosure

Type	Outline and Features
Shielded		A metal enclosure shields the sides of the detection coil. The sensor can be embedded in metal as it is less affected by the surrounding metal. (GX-3S□, GX-4S□, GX-5S□, GX-5SU□ require a small clearance at the front sensor end.)
Non-shielded		The sides of the detection coil are not shielded by a metal enclosure. [All resin-enclosed sensors (GX-F/H series, GXL series, GL series) are non-shielded types.] They have a longer sensing range than a shielded type of the same size. Since it is easily affected by surrounding metal, care should be taken that metal other than the sensing object does not come near the sensor front end.

Type

Outline and Features

Shielded

A metal enclosure shields the sides of the detection coil.
The sensor can be embedded in metal as it is less affected by the surrounding metal.
(GX-3S□, GX-4S□, GX-5S□, GX-5SU□ require a small clearance at the front sensor end.)

Non-shielded

The sides of the detection coil are not shielded by a metal enclosure.
[All resin-enclosed sensors (GX-F/H series, GXL series, GL series) are non-shielded types.]
They have a longer sensing range than a shielded type of the same size.
Since it is easily affected by surrounding metal, care should be taken that metal other than the sensing object does not come near the sensor front end.

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(3) Classification by output circuit

ON / OFF output

Type

Outline and Features

NPN open-collector
transistor

Able to drive a relay, PLC, TTL logic circuit, etc.
A separate power supply can be used for the load.
Long life
High-speed response
Commonly used in North America or Japan

Symbols

D	:	Reverse supply polarity protection diode
ZD	:	Surge absorption zener diode (Its position differs with the model.)
Tr	:	NPN output transistor

PNP open-collector
transistor

Commonly used output circuit in Europe
Power supply is not required for the load.
Long life
High-speed response

Symbols

D	:	Reverse supply polarity protection diode (Its position differs with the model.)
ZD	:	Surge absorption zener diode (Its position differs with the model.)
Tr	:	PNP output transistor