Inductive proximity sensors are the preferred choice for the majority of applications requiring accurate, non-contact detection of metallic objects in machinery or automation equipment. As a pioneer and market leader, Pepperl+Fuchs offers innovative, high quality inductive sensors to meet the needs of the worldwide automation and process control markets. Our experience, flexibility and customer focus continues to allow us to offer custom designed solutions for the most unique and demanding applications.

Standard Inductive Sensor Product features:

• Smooth or threaded stainless housings
• Polarity reversal and short-circuit protected
• LED status indication
• Connection styles include M8, M12 or terminal connection models
• Models with PVC, PUR or silicon cable
• Outputs in 2-, 3-, 4-wire DC, AC, NAMUR, and AS-Interface versions

Application Specific Inductive Sensor features:

• Analog output models with 4-20 mA output signal
• Integrated speed monitor with up to 100 Hz operation
• Pressure resistant cylinder sensors for up to 500 bar
• Sensors approved for gas and dust Ex zones
• Models with stainless steel sensing face
• Protective class of up to IP68/ IP69k (submersible/ high pressure water jet resistant)
• Weld resistant designs with PTFE-coated surface
• Reduction factor of 1, all metals sensed at same distance
• Exclusive ferrous and non-ferrous detection models
• Safety function sensors
• Extended temperature range: -40 °C up to +250 °C

1. Proximity switch with "Metal Face"

Some applications place particularly high demands on the robustness of sensors. These rugged and durable "Metal Face“ sensors are enclosed in stainless steel making them the best selection for these tough applications. Applications such as machine tools or metal processing will often expose the sensor to target impact, abrasion and the affects of aggressive solvents and fluid.

2. Inductive analog output sensors

Inductive analog output sensors are used to detect metal objects within specific operating ranges. This object distance is then translated into an analog output signal proportional to distance, making these sensors ideally suited for measuring and control applications. The Pepperl+Fuchs product offering includes operational detection ranges from 2 … 5 mm, 3 ... 8 mm, and 15 ... 40 mm. Due to the low temperature deviation of our inductive analog sensor product, only 1/1000 of the final value per degree Celsius, the sensor remains reliable and accurate even under non-constant ambient conditions.

In these applications, sensors with a stainless steel sensing face may reduce down time and extend service-life making your overall production more profitable.

Our "Metal Face“ product series (NMB…) is available in 2 versions, (FE) for detection of ferrous metals and (NFE) for detection of non-ferrous metals.

3. Bus-enabled proximity switches

In multiple sensor applications, a communications network often connects sensors so that system coordination can be accomplished. We offer a line of intelligent proximity sensors that extend their functionality to include supply line monitoring, diagnostics and network communication with a programmable logic controller.

Using our AS-interface proximity sensors the user can network up to 31 (specification 2.0) or 62 (specification 2.1) proximity switches per master.

Proximity switches with AS-interface are equipped with a failure warning indication, a on/off switching delay, and an internal oscillator monitoring function. These sensors are available in cylindrical, rectangular and screw-on "F" design housing styles.

4. Pressure-resistant proximity switches

Pressure-resistant proximity switches are suitable for use in hydraulic actuators and cylinders. The sensors are able to withstand pressures up to 350 bar (M18 cylindrical style) or 500 bar (M12 cylindrical style) exerted dynamically onto the active surface.

5. Proximity switches with increased switching distance

For some applications proximity sensors with increased switching distance can be used to solve detection problems such as small object detection or overcoming the effects of material dependent reduction factors.

In addition, these extended range sensors may be used to solve issues such as:

mounting restrictions, mechanical tolerances or for detection through protective coatings. For these areas of operation Pepperl+Fuchs offers a proximity switch series with increased sensing range.

6. Proximity switches with NAMUR output

The voltage and current characteristics of NAMUR output switches are so low that they can be safely used in explosive environments. Product model numbers with an "N“ after the identification, sometimes combined with a number, identify this product family.

The power limitation is implemented in the corresponding equipment. This means that the circuit containing a NAMUR proximity sensor is only intrinsically safe if it is supplied via a corresponding isolating amplifier.

7. Proximity switches for valve actuators

Ring style proximity switches are fitted with a coil so that the switch is activated as soon as a metallic object is found inside the circumference of the ring.

Typical applications include the detection and counting of small metal parts, which are passed through the ring proximity sensor. Both ferrous (FE) and nonferrous (NFE) metals will be detected.

8. Slotted proximity sensors

Slotted proximity sensors consist of a two coil system sensing across the slot opening. If a piece of metal is inserted into the slot sensor, the inductive coupling between coils will be reduced based on the depth of the target metal. Once this coupling falls below its critical value the proximity switch will be activated.

Due to the nature of the sensor design, this type of proximity switch is less affected by metal characteristics as well as being less sensitive to target position changes in the direction of the core axis.

9. Proximity switches with protection category IP69k

Under certain environmental conditions the reliability of standard sensors cannot be guaranteed for long operational life. For example, if a standard proximity sensor is exposed to high-pressure water jets in a car wash system, water can forced into the sensor and create a potential cause for failure. For this reason Pepperl+Fuchs designed in new sensor features to reduce the effects of high pressure environments and ensure problem-free use in such applications.

Design features of our proximity switches include a tighter construction fit of mechanical parts such as plastic caps and sensor housing, plasma cleaning of all surfaces to which sealant is applied and the pre-sealing of the coil system. This allows for characteristics to be achieved which are significantly above the test requirements for IP67/ IP68 ratings.

10. Proximity sensors for use in strong DC and AC fields (weld-proof)

Proximity sensors used in welding systems are characterized by their high resistance to strong magnetic fields and an increased mechanical robustness suitable for the rough ambient conditions. This family of sensors has a sensing face made of durable Ryton to protect against molten metal plus a weld resistant coated brass housing.

11. Proximity switches with selective detection (ferrous/ non-ferrous)

With these proximity switches it is possible to differentiate between ferrous and non-ferrous metals. To accomplish this these proximity switches come with 2 separate outputs. One output for signaling ferrous metal detected and one output to signal that a non-ferrous metal is detected.

12. Proximity switches with safety function

These proximity switches correspond to the NAMUR product type but offer the following specific behavior: In case of malfunction of the sensor, the control interface unit or the common power line the output of the control interface unit will automatically switch into the safe "off" condition.

These sensors are identified by SN or S1N after the identification. The safety function can only be guaranteed in conjunction with appropriate control interface units.

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