Smart inductive sensors help recycling companies benefit from fast accurate sorting of mixed-metal waste


The global recycling industry continually seeks to reduce the cost of sorting and separating mixed-metal scrap. With the introduction of induction sorting, designers require sensors that operate accurately and at high speed to identify and separate fast-moving streams of ferrous and non-ferrous material in a single pass. Rugged inductive Smart Sensors from Contrinex, embedded immediately below the delivery belt, provide continuous high-speed detection across the full width of a conveyor.

Customer Values

  • Embeddable inductive Smart Sensors differentiate clearly between target material types, detecting non-ferrous metal and triggering separation accurately and reliably
  • A single array of sensors provides continuous detection across the full width of a conveyor
  • Smart Sensors are easily able to identify material on fast-moving conveyors thanks to 1000 Hz sensing frequency
  • Industry-standard IO-Link connectivity provides a single interface to the machine control system
  • Cumulative operating data for predictive maintenance, including temperature and operating-cycle count, is recorded in on-board data storage
  • Sensor configurations are stored locally, allowing plug-and-play replacement of sensors when needed
  • Proven technology ensures highly reliable fit-and-forget operation with no manual intervention

Specific Product Advantages

  • Robust, metal-cased inductive Smart Sensors are ideal for easy integration
  • Multi-channel monitoring circuitry allows users to define up to 5 customized output thresholds
  • Sophisticated sensing electronics deliver high-precision analog output signals
  • High-speed device-to-device communication enables decentralized data-processing and decision making
  • Smart Sensors are individually shielded and EMC immune, eliminating interference when multiple devices operate in close proximity
  • Dedicated service-data blocks hold device-specific data including product ID, location and serial number
  • Visible LED indicators enable sensors to self-identify on demand, simplifying commissioning and trouble-shooting routines
  • Industry-standard -25°C to +70°C operating range

Customer Application

The global recycling industry relies on advances in technology to automate waste-recovery operations, making it economic to recover an ever greater proportion of domestic and industrial waste. In recent years, waste-management companies have been looking for more affordable alternatives for sorting and separating mixed-metal scrap; existing processes, while effective, are inflexible and expensive.
In recent years, enhanced sensor capabilities have seen the introduction of induction sorting, a process that identifies and separates different types of metallic material. A fast-moving conveyor carries pre-sized waste over a bank of inductive sensors mounted below the belt; the sensors detect and identify any non-ferrous material, which is subsequently ejected and separated by a targeted air-knife.
To take full advantage of the process, OEM equipment builders require robust sensors that differentiate accurately and at high speed between ferrous and non-ferrous material, allowing a single bank of sensors to process mixed-metal waste in a single pass. As the sensors may operate independently or in combination with other sensing technologies, an industry-standard communication interface is highly desirable.

Customer Solution

Designers specified rugged inductive sensors from the Contrinex Smart Sensor portfolio; an array of 50 metal-cased sensors, embedded in a grid pattern immediately below the belt, provides continuous detection across the full width of the conveyor. Best-practice electronic design ensures that Smart Sensors are individually shielded and EMC immune, eliminating interference when multiple devices operate in close proximity.
Mounted only a few millimeters from the target as it passes overhead, these M18 devices, which have a nominal sensing distance of 10 mm for carbon steel, generate analog output signals that vary according to the material type. With a sensing frequency of nnnnn Hz, Smart Sensors are easily able to accommodate the required range of conveyor speeds.
IO-Link connectivity, standard across the range, provides an industry-standard interface to the machine control system, triggering the appropriate air-knives as pieces of non-ferrous material reach the separator. During initial calibration, each sensor’s configuration is stored automatically on the local IO-Link Master; this allows plug-and-play replacement of sensors should the need arise, without any loss of functionality and without any need for recalibration.
Contrinex inductive Smart Sensors are designed with the needs of OEMs and system integrators in mind and provide an unobtrusive fit-and-forget solution. On-board data storage holds cumulative operating data for user-specified purposes, including predictive maintenance. These highly versatile sensors meet designers’ needs for a robust and cost-effective solution that delivers exceptional accuracy and reliability in a particularly challenging environment.