Serviceline Industrial Sensors
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Installation Conditions

The installation conditions provide information about optimal installation of the sensors in the application without being restricted in their specified function (i.e., their operating distance). Due to the given installation conditions, a functional range must always be assumed. There is a connection between installation and operating distance.

Cylindrical Inductive Sensors

Sensors with the same diameter may have different operating distances for installation-related reasons, as shown in the following table.

Diameter [mm]

Operating distance [mm] with flush mount

Operating distance [mm] with nonflush mount

Extended operating distance [mm]





















Nonflush-Mountable Inductive Sensors

Nonflush-mountable inductive sensors achieve the largest possible operating distance in relation to their diameter. Inductive sensors use coils to generate the electromagnetic field. To achieve the required orientation of the electromagnetic field, these coils are usually wound in a pot-type core. Nevertheless, some of the electromagnetic field is emitted from the side.  It is essential to have clearance around the sensor element. This prevents such long-range sensors from being attenuated by the surroundings. This clearance should not be less than the following minimum values.

Left: nonflush-mountable inductive sensor, correctly installed 
Right: flush-mountable inductive sensor, correctly installed

A = 2 x operating distance (sn)

B = 3 x housing diameter (d) of the sensor

D = housing diameter of the sensor

F = minimum distance of similar sensors

Flush-Mountable Inductive Sensors

Flush-mountable inductive sensors can be installed in metal such that they do not protrude forward (dimension A = 0 mm). This has the advantage that these sensors are more mechanically protected and less sensitive to interferences than nonflush-mounted sensors. The required reduction of the lateral field is achieved by special internal shielding. This is done at the expense of the detection range: These sensors achieve only about 60% of the operating distance in comparison with nonflush-mounted versions.

Left: flush-mountable inductive sensor, correctly installed
Right: nonflush-mountable inductive sensor, correctly installed

A = 2 x operating distance

B = 3 x housing diameter of the sensor

D = housing diameter of the sensor

F = minimum distance of similar sensors


Inductive sensors can be flush mounted in conductive material and are relatively insensitive to electrical or electromagnetic influences. When inductive sensors are installed flush, they only reach 60% of the sensing range of a nonflush-mountable sensor of the same housing design. To compensate for this, correspondingly larger-dimensioned sensors must be selected.

Semi-Flush Mounting of Inductive Sensors with Extended Operating Distance

Inductive sensors with a highly extended operating distance cannot be mounted completely flush in metal. They are referred to as "semi-flush mountable."

  • Ferromagnetic materials: A= 0.2*d
  • Nonferromagnetic materials: A= 0.1*d
  • Nonconductive materials: A=0

At Pepperl+Fuchs, this applies to sensor types NEB and NEN.

Cross-Talk When the Minimum Distance Is Not Reached

The specified minimum distances F must be observed to prevent cross-talk of similar sensors. Inductive sensors with offset frequencies can be used if there are difficulties observing the minimum distances in a particular application. If offset frequencies are used, inductive sensors can be mounted directly next to one another. Such cases are customized solutions and can be provided by Pepperl+Fuchs upon request.

Nonflush-mountable inductive sensor: minimum distance F should be three times the housing diameter

Flush-mountable inductive sensor: minimum distance F should be one times the housing diameter

Cubic Inductive Sensors

Similarly, cubic sensors have precise installation conditions for flush, nonflush, or semi-flush mounting. As with cylindrical sensors, minimum distances must be observed between the individual sensors. The rules are specific to the product series and are available as installation information for the selected sensor.


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Take a look at the range of Pepperl+Fuchs inductive sensors.