Optical encoders for non-contact measurement
Encoder wheels, length encoders and speed encoders are classic sensor devices for process control when producing strip material, e.g. in steel mills or paper manufacturing. Knowing the exact strip length and the current velocity is essential for optimizing a manufacturing process. Here, Polytec offers a non-contact solution of length and speed encoders for next level process control. Learn more about how ProSpeed®optical encoders will take your production process control to the next level.
Highlights of optical encoders
//- Reliable in-line measurement of length and speed plus standstill
- Optical speed & length encoders avoid contact, slippage and wear
- Rely on wear-free optical encoders
- Robust sensor technology for harsh and hot environments (IP66 and IP67); certified mechanical shock and vibration resistance
- Outstanding measurement depth-of-field up to 200 mm compensates varying distances
- Transparency thanks to enhanced connectivity (web interface, Ethernet, fieldbus protocols)
- Multi-user access (3 via Ethernet + 1 serial)
- High flexibility with up to 3 m long stand-off distances
Why use optical encoders for process control?
ProSpeed® laser sensors are high-performance optical encoders, replacing conventional encoder wheels for a more reliable length and speed measurement. The non-contact way of ProSpeed® optical encoders capture length and speed with laser precision, avoiding contact, showing zero influence on the measured surface and eliminating classic backdraws of traditional encoders such as slippage, wear resulting in measurement uncertainty and scrap. ProSpeed® optical length and speed encoders are desigend to perform under harsh conditions and in challenging industrial environments. ProSpeed® optical sensors offer a high level of robustness and process integrity at minimal maintenance cost.
Applications of laser encoders in industrial process control
Optical speed encoder applications
Monitoring the exact process speed or inline velocity measurement is key for many steps in production processes such as cut-to-length control, from extrusion and converting to steel casting, elongation and metal rolling processes, sometimes speed synchronization, or differential speed measurement and more. In these industrial manufacturing processes, optical speed encoders use the laser Doppler effect for precise speed measurement, avoiding contact of the encoder with the good's surface and preventing slippage and wear, resulting in utmost precision and reliability in process control.
Optical length encoder applications
Whether in casting processes, rolling mills or any cut-to-length control, length verification of cut products such as rods, tubes, coils, panels and sheets, plate positioning in U- and O-presses for tubes, material tracking for sheet materials, winding sheet material up to position sensing and elongation, with length of a final or semi-finished product being the key factor for process control, laser encoders like ProSpeed LSV have become the established optical sensor of choice in many production lines.
Optical encoders for cut-to-length, casting and rolling mills
Providing electrical signals just like any classic encoders, optical encoders can seemlessly be integrated into manufacturing lines for inline measurement. Laser encoders show exceptional performance in challenging conditions such as red-hot metals, humid and hot or dustry production environments, providing stable and all-time reliable measurement signal for continuous production, reducing measurement uncertainty caused by slippage or wear.
Optical encoders promise reliable measurement data
Polytec optical length and speed encoders, so called LSV Laser Surface Velocimeters, are established optical sensors in many applications to optimize the process by reducing process variability. LSV are established length and speed encoders installed in applications such as cut-to-length control, part-length verification, total length on winders, line speed, differential line speed for stretch or elongation and many more. Avoid process uncertainty and added costs caused by contact measuring techniques like encoder wheels due to slippage, wear, damage to the product or maintenance.
ROI calculation of optical encoders in industrial process control
Example calculation of ROI and emission reduction in a 5-strand billet caster using ProSpeed® optical length & speed encoders.
How it works: optical encoders for in-line process control
ProSpeed® as the optical alternative sensor solution compared to encoders or encoder wheels use the laser Doppler effect to evaluate the laser light scattered back from the moving object. Two laser beams super-imposed on the surface generate an interference pattern of bright and dark fringes. As the surface moves through the fringe pattern, the intensity of the light scattered back modulates in frequency. This modulation frequency measured by the photo receiver of the sensor system is directly proportional to the surface velocity.
Encoder integration using PROFINET or Ethernet/IP
The latest ProSpeed® LSV sensor generation comes in a rugged, compact design featuring integrated optics and advanced electronics, providing faster signal response, and more stable signal level for real-time process control. The extended connectivity allows simple and smooth sensor integration into automated processes. With a wide range of accessories and the support of our PolyXperts team, Polytec offers sensor solutions tailored to your processes.
For automation, login and read in these step-by-step application guides on how to easily integrate ProSpeed® laser encoders with PROFINET or EtherNet/IP or contact us!
