top of page
SENSORS
Wenglor Inductive Ring Sensors
Reliable Detection of Small Metal Parts in Feed Hoses
What is an Inductive Ring Sensor?
An inductive ring sensor is a specialised inductive sensor designed to detect metallic objects as they pass through a ring-shaped sensing field.
Rather than detecting an object from one side, as with a conventional inductive proximity sensor, the feed hose or tube passes through the centre of the sensor. Metallic components travelling through the hose can therefore be detected anywhere within the active field.
Wenglor's inductive ring sensors are designed for the fast and reliable detection of small metallic components in feed hoses, including applications where contamination may be present. Depending on the model, metallic parts as small as 2 mm can be detected.
How does an Inductive Ring Sensor work?
The sensor creates an electromagnetic field around the inside of its ring opening. When a metallic object passes through this active field, it changes the electromagnetic conditions within the sensor. The sensor detects this change and generates a switching signal that can be sent to the machine controller or PLC.
This makes ring sensors particularly useful for monitoring small metallic components moving rapidly through pneumatic feeding systems—for example:
screws, nuts, rivets, washers, pins and other metallic fasteners.
The Wenglor design is available with both static and dynamic operating principles. Static sensors can detect rapidly moving objects as well as objects remaining within the ring, making them suitable for applications such as bottleneck monitoring. Dynamic versions are designed specifically for detecting small, fast-moving objects, such as monitoring the ejection or passage of rivets.
What makes the Wenglor Ring Sensor different?
One of the most interesting aspects of this sensor is not simply the inductive sensing technology—it is the mechanical design.
Separable housing – install it without disconnecting the hose
The sensor housing and sensing coil can be opened.
This allows the ring sensor to be fitted around an existing hose, rather than requiring the hose to be disconnected and fed through a permanently closed sensor.
For maintenance teams, this is a significant advantage. The sensor can be installed or removed quickly when replacing hoses, modifying equipment or carrying out repairs, potentially reducing machine downtime. The two-part coil still enables metallic objects to be detected throughout the active sensing field.
Correction Factor 1 – reliable detection of different metals
Different metals normally influence an inductive sensor differently.
Wenglor addresses this with Correction Factor 1 technology. The sensors can reliably detect different non-ferrous metals, with correction factors for stainless steel, brass and aluminium specified at 1/1/1 on the individual products.
This is particularly valuable where different metallic components or alloys may pass through the same production equipment.
Detect metallic parts from just 2 mm
For suitable models, the dynamic range can detect metallic objects with a diameter as small as 2 mm.
For example, Wenglor's IR2D001 has a 10.2 mm inside diameter and specifies a smallest recognisable object of 2 mm. It can detect objects travelling between 0.1 and 50 m/s and has a response time below 300 μs.
This makes the technology particularly well suited to high-speed automated feeding and assembly systems.
Secure mounting without restricting the hose
A flexible soft binder secures the sensor to different hose sizes.
Importantly, the mounting arrangement is designed so that it does not taper or constrict the hose. The mounting system also provides stable fixation in environments subject to vibration.
This becomes particularly relevant with vibrating spiral feeders and compressed-air conveying systems.
Designed for tight machine spaces
Wenglor routes the electrical connection parallel to the hose rather than outward from the sensor.
This reduces the installation envelope, avoids cable kinking and prevents the connector and cable from obstructing the surrounding machine design.
Wenglor also incorporates weproTec technology, allowing multiple sensors to be positioned close together without interfering with each other.
360° visible switching indication
A particularly useful feature for commissioning and fault finding is the all-round visible LED indication.
The operating status can be seen regardless of the sensor's mounting orientation:
Blue – power supply
Yellow – switching operation
Red – error
IO-Link connectivity
The Wenglor inductive ring sensor range also incorporates IO-Link 1.1 on applicable models.
IO-Link allows sensor parameters and process information to be communicated digitally to the automation system, providing considerably more functionality than a simple ON/OFF switching signal.
Wenglor specifies adjustable parameters including sensitivity, frequency switching and error indication on the current ring sensor portfolio.
This makes the sensor particularly suitable for modern automated machinery where diagnostics, parameterisation and sensor data need to be integrated into the control architecture.
Typical Inductive Ring Sensor applications
The technology is especially suited to automated assembly and feeding systems.
In these systems, fasteners such as screws, nuts and rivets are automatically sorted and transported through feed hoses, often using compressed air. A ring sensor fitted around the hose confirms that the component has actually passed the monitoring point.
Wenglor specifically identifies applications including presence monitoring, bottleneck monitoring, size differentiation and wire-break detection.
Automotive manufacturing
In automated punch-riveting applications, aluminium or brass components can be pneumatically transported through plastic hoses to the riveting equipment. The inductive ring sensor monitors the hose and confirms the passage of the component, including components of different sizes and alloys.
Assembly and feeding technology
Automated feeding systems transport and separate screws, nuts, rivets and other fasteners before supplying them to assembly equipment.
Wenglor's ring sensors can be mounted directly around the feed hose to detect metallic components travelling through it at high speed.
Static or Dynamic Ring Sensor – which should you use?
Static ring sensors can detect moving objects as well as metallic objects that remain within the sensing area. They are therefore useful where the sensor may need to detect a blockage or component that has stopped inside the ring.
Dynamic ring sensors are optimised for detecting small objects moving through the sensor and are particularly useful for high-speed component counting or ejection monitoring.
The appropriate version therefore depends on the component size, hose diameter, material, object speed and whether stationary components must also be detected.
Why use a ring sensor instead of a conventional inductive sensor?
The principal advantage is the sensing geometry.
A conventional inductive sensor monitors a relatively localised area in front of its sensing face. A ring sensor surrounds the component path, making it particularly suitable where small metallic parts may travel through different positions within a tube.
Combined with the Wenglor sensor's separable housing, high-speed detection, Correction Factor 1 and IO-Link interface, this provides a purpose-built solution for monitoring metallic components in automated feeding systems.
Wenglor Inductive Ring Sensors in South Africa
ASSTech supplies Wenglor industrial sensors and automation technology in South Africa.
If you are experiencing missed components, feed errors, blocked hoses or unreliable detection of small metallic parts in an automated assembly or feeding system, we can assist in selecting the appropriate Wenglor ring sensor according to your:
hose diameter · component size · component material · feed speed · static/dynamic requirement · electrical output · control system
FAQ
What is an inductive ring sensor?
An inductive ring sensor detects metallic objects passing through its ring-shaped sensing field. It is commonly installed around feed hoses carrying screws, nuts, rivets and other small metallic components.
Can an inductive ring sensor detect aluminium?
Yes. Wenglor's Correction Factor 1 technology is designed to reliably detect different metals including aluminium, brass and stainless steel.
How small an object can a Wenglor ring sensor detect?
Depending on the model, Wenglor specifies detection of metallic objects from 2 mm.
What is the difference between a static and dynamic ring sensor?
A static sensor can detect moving objects and objects remaining inside the sensing field. A dynamic sensor is intended for detecting small, fast-moving components passing through the ring.
Can the sensor be installed without disconnecting the hose?
Yes. Wenglor's separable housing and two-part coil allow the sensor to be opened and installed around an existing hose.
bottom of page