Pepperl Fuchs inductive sensors Instruction Manual

Installation conditions for inductive sensors

D

F

A

B

Non-flush proximity
switches, properly
installed

Flush proximity
switches,
properly installed

B = diameter D

A = 2 x switch­ing distance

Non-flush installed proximity
sensors, F must be 3 times the
housing diameter

Flush installed proximity sen­sors, F must be equivalent to
the housing diameter

A

C

B

Metal

F

F

Installation condition

The given values are minimum values. They cause changes of the
sensing range less than 10%.

Cylindrical proximity switches

Devices with the same diameter may have different switching dis­tances. The following table shows typical examples:

Diameter

[

mm]

6.5 2 3 3
8 2 3 3

12 2 4 6
18 5 8 12
30 10 15 22

flush not flush

Proximity switches that are installed non-flush

The largest possible switching distance (relative to the diameter) is

chieved by proximity switches that are installed non-flush. An in-

a
ductive proximity switch utilizes coils for generating the electromag­netic field. To achieve a particular direction of the field these coils
are wound in an encapsulated core. Nonetheless, some of this field
will radiate sideways.

To avoid these products with a large range to be already attenuated
by the environment, a clear space must be created around the sen­sor element complying with the minimum values in the following ta­ble.

Dimensions [mm]

A B F

2 x S

n

Switching distance

B = D

increased switching

distance, flush

flush F = D

not flush

F = 3 x D

Sensors with increased switching distance

These sensors with extremely increased switching distance cannot
b

e installed fully flush in metal. They are described as semi-flush in-

stalled.

Distance [mm]

Type

NEB 3-6,5... 1,0 0 6 9 16
NEB 6-12... 2,0 1,0 6 18 18
NEB 12-18... 4,0 1,5 12 36 26
NEB 22-30... 6,0 1,5 22 66 50
NEN 6-8... 8 8 8 18 20
NEN 10-12... 12 12 12 30 30
NEN 20-18... 22 22 22 60 60
NEN 40-30... 40 40 40 120 120

A

(steel, nonfer-

rous heavy

metal)

A

(stainless

steel)

B C F

Proximity switches that are installed flush

Flush installed inductive proximity switches can be used without

earance (A = 0). An advantage is that they are thus mechanically

cl
better protected and less sensitive to erroneous effects than non­flush installed types. The required reduction of the lateral field is
achieved by a special internal shielding. This is at the expense of the
range; these proximity switches only achieve approx. 60 % of the
switching distance of designs for non-flush installation.

Mutual interference

The minimum distances F specified in the table above must be kept

o prevent any mutual interference. If these distances cause prob-

t
lems with the application, then proximity switches with offset fre­quencies are available upon request. These can then be installed
directly adjacent.

If in doubt please enquire.

Date of issue 2018-02-13

Mutual interference

To prevent the mutual interference between two similar sensors the

inimum distances specified in these tables must be kept.

m
For applications where these distances cannot be maintained prox­imity switches with offset frequencies are available upon request.
These can then be installed directly adjacent.

Please talk to our product specialist.

1

Sensors with Reduction Factor 1

A

C

B

mild steel

F

F

Distance [mm]

Type

NRB2-6,5… 0 5 10 20
NRN6-6,5… 10 20 20 30
NRB2-8G… 0 5 10 15
NRN6-8G… 10 20 20 25
NRB4-12G… 0 5 15 15
NRN10-12G… 20 30 30 50
NRB8-18G… 0 5 15 20
NRB12-18G… 5 15 20 20
NRN15-18G… 25 30 40 60
NRB15-30G… 0 15 20 35
NRN30-30G… 30 45 80 160

A

(for installation in

mild steel)

B C F

Date of issue 2018-02-13

2