Capacitive Proximity Sensors Technical Description and Operating Principles

Capacitive Proximity Sensors
Technical Description and Operating Principles

>> For more information visit our new website www.sah.co.rs <<

Main Features	Operating Principles	Applications
Description and sensor model naming
	Dielectric constants

Main Features

●	Small size
●	High precision repetition
●	Various external forms
●	Good interference resistance
●	Many output forms
●	High switching frequency
●	Wide voltage range
●	Sealed against dust, vibration resistant, sealed against to water and oil
●	Protected against short circuit and reverse wiring
●	Long life

Operating Principles

Induction surface capacitive sensor consists of two coaxial metal electrode comprising a capacitor connected to the RC oscillating circuit, as a capacitor with an open capacitive electrode. By attaching the power RC oscillator is not working. When the subject is close to the electrode capacitance, electrolytic capacitors increases, and the oscillator oscillates. With signal processing in the following circuits the start and stop of oscillator is converted into switching signals which checks the presence (existence) of the object. This sensor detects metallic and non-metallic objects. For metal objects maximum distance can be achieved, while with non-metallic objects detection distance depends on dielectric constant - with higher constant longer detection distance can be achieved.

Applications


Measuring the level of liquid in a plastic or glass court	Measurement of material

Check the break	Count bottle

Detection of tension belt conveyor	Detection and counting

Description and sensor model naming

No.

Description

Codes and definitions

Switch Category

CM: Capacitive type

Shape

□: cylinder type F: square and planar type

Operating voltage

30:

6~36VDC

310:

5~24VDC

320:

12~60VDC

20:

90~250VAC

210:

24~250VAC

220:

380VAc

4:

12~240VDC/24~240VAC

5:

Special voltage

Detection distance

01:

1mm

05:

5mm

10:

10mm

Output format

N:

3-wire DC NPN output

P:

3-wire DC PNP output

L:

2-wire DC output

□ :

2-wire AC output

W:

3-wire AC output

J:

Relay output

NP:

NPN+PNP dual output

Output state

A:

Normally open (NO)

B:

Normally closed (NC)

C:

Normally open + Normally closed (NO+NC)

MU:

Voltage

MI:

Current

Addition features

T:

With connector

Y:

Impermeable to water and oil

I:

By special request

H:

Resistant to high temperrature

R:

Ring type

Dielectric constants

Material	Dielectric constant	Material	Dielectric constant
Synthetic resin	3,6	Water	80
Mica	6	Alcohol	25,8
Ebonite	4	Glass	5
Marble	8	Cardboard	4,5
Paper	2,3	Cable rubber compound	2,5
Organic glass	3,2	Petrol	2,2
Styrene	3	Polyvinyl	2,9
Porcelain	4,4	Quartz glass	3,7
Wax	2,2	Silicon	2,8
Quartz sand	4,5
Soft rubber	2,5