Special Sensors

Sensors optimized for use in special application areas can be found below. These are application-specific sensors.

Reduction factor 1 sensors detect all metals with virtually the same operating distance. This offers benefits compared to conventional inductive sensors. This is especially true for applications in which a sensor is being used to detect different metals.

Features:

• Same operating distance for all metals
• Maximum operating distances from 2 mm ... 75 mm
• Electric magnetic field immunity
• Mechanical welding resistance (optional)
• Complete portfolio of cylindrical and cubic housing designs

In order to successfully survive in harsh industrial environments, inductive sensors used in welding systems have a correspondingly high level of mechanical robustness and high immunity to strong magnetic fields.

These weld-proof sensors have a front face made of polyphenylensulfide (PPS) to protect against molten metal beads produced during welding. For welding-bead resistant cylindrical sensors, the housing is made of PTFE coated brass.

Refer to the Materials section for detailed information about individual material versions of inductive sensors.

Metal face sensors from Pepperl+Fuchs consist entirely of stainless steel. In some applications, particularly high demands are placed on the robustness of sensors. When sensors are used in machine tools, the sensor is exposed to high forces, abrasion, and aggressive media. In such applications, sensors with a stainless steel sensing face are used to ensure a long service life.

The food and beverage industry environment places high demands on machinery and components. For this reason, Pepperl+Fuchs has developed special sensors for this industry, taking into account the current standards. These sensor solutions comply with worldwide standards and directives for the food and beverage industry, such as those of European Hygienic Engineering and Design Group (EHEDG) and the FDA.

Pressure-resistant sensors are suitable for use in applications such as hydraulic actuators. These sensors can be used at operating pressures of up to 500 bar and peak pressures of up to 800 bar on the sensing face.

The pressure resistance is achieved by a ceramic front face that is an integral part of the stainless steel housing. There is also a groove incorporated into the housing for an O-ring.

Different solutions and correspondingly different versions exist for monitoring valve actuators

1. Integration of standard sensors in control boxes
2. Use of special position feedback sensors in control boxes or in direct assembly
3. Use of special position feedback sensors

Sensors for Installation in Control Boxes

Valve actuators have control boxes, i.e., small housings mounted in a fixed position on the drive. These house technology such as sensors for position feedback. The control box is used for the mechanical coupling of the sensors to actuating drives in different dimensions. This solution prevents the sensors from being directly exposed to the environment and therefore allows the use of conventional standard sensors.

Most reputable drive manufacturers offer standard boxes fitted with Pepperl+Fuchs sensors, either with or without optical display.

Features:

• Individual connection options
• Control box protects the built-in electrical installation from contamination and tampering
• Control box complies with accident prevention regulations
• Mounting using pre-aligned sensor technology
• Correct connection marking of instrumentation and control equipment and mechanical mounting according to specifications of VDI/VDE 3845

Possible Sensor Types for Installation

Various Pepperl+Fuchs sensors are suitable for installation in control boxes. These sensors are:

• Cylindrical standard sensors with short lengths of up to 40 mm
• Inductive slot sensors with a slot width of 3.5 mm
• Sensors from the V3 product family: cubic sensors in the standard dimensions of mechanical microswitches

Standard DC versions or NAMUR versions with an extended temperature range of up to -50 °C ... +100 °C can be used as output stages.

Dual Sensors for Open Assembly

Dual Sensors from the -F25 Product Family

The -F25 sensor product family offers open solutions for position feedback, especially of manually operated ball valves and flaps.

This sensor type combines two devices as dual sensors in one housing and considerably reduces the mounting and maintenance costs.
Sensors from the -F25 product family are suitable for direct assembly on the valve actuator.

Features:

• The dual sensor has two active zones
• The sensor complies with accident prevention regulations: The design makes it impossible to accidentally insert fingers between the actuator and the sensor
• Mounted directly on the drive or on the fitting, using a bracket or in the control box
• Mounting does not require any additional settings
• Multiple sensors can be stacked if more than two switch points are required

-F31 / -F31K Product Family

The -F31 and -F31K product families are open solutions for position feedback. The sensor and actuator can be mounted directly and are stable and impact-resistant. Sensors for open assembly are suitable for direct assembly on drives without additional mounting material. With two actuators, the user can query the position of all standard drives regardless of size and make.

The -F31K product family offers a terminal compartment with spring-cage terminals or with screw terminals for system connection and valve connection. Sensor versions with zero, one, or two valve connections are available. The valve can therefore be controlled directly via the sensor connection as required. This reduces assembly effort and cabling costs.

Features:

• Sensor design and distance to actuator have been proven to eliminate risk of injury
• Sensors are suitable for all standard drives
• Mounting holes in the sensor housing allow the adjustment to be maintained when the sensor is replaced
• Left-rotating and right-rotating drives can be requested
• Assignment of the actuator to the hole pattern for the drive is clear and the drive position is highly visible
• Choice of cable connection, plug connection (V1, V16, or V18) or terminal compartment connection 
• Switch states, the supply voltage, and the valve control are clearly shown via LEDs

-F31K2 Product Family

The -F31K2 product family has a modular, mechanical design. This means that sensors in this product family can be easily integrated into drives in various ways. The -F31K2 product family offers numerous versatile components for every intended purpose, such as an actuator with a display unit to make the valve position visible from a distance, or a matching stainless steel cover, which mechanically protects the sensor against damage.

Features:

• Open solution for valve position feedback on valve actuators for use in explosion-hazardous areas
• System can be used "fully protected" with a protective cover and "puck+beacon" or with a standard activator and protected installation
• F31K2 3G/3D is particularly suited to harsh conditions and in explosion-hazardous areas. Sensor has an ATEX certificate, a temperature resistance of up to -40 °C, and a resistance to impact of up to 7 J.