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.

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.

Onsite support, 3yrs warranty, sensor exchange - with our PolyXpert services, you are on the safe side!

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
  • High flexibility with up to 3 m long stand-off distances
  • 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)
  • Robust sensor technology for harsh and hot environments (IP66 and IP67); certified mechanical shock and vibration resistance

Applications of laser encoders in industrial process control

Precise speed and length measurement on drywall boards
Precise speed and length measurement on drywall boards

Speed encoder applications

Process speed or velocity measurement is the basis for many steps in production processes such as cut-to-length control, depending on the manufacturing process sometimes speed synchronization, or differential speed measurement and more. In these 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.

Speed and tension control for industrial cable and wire production, casters and strip goods
Speed and tension control for industrial cable and wire production, casters and strip goods

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.

Continuous casting line with ProSpeed LSV-2100 laser sensor measuring casting speed and length
Continuous casting line with ProSpeed LSV-2100 laser sensor measuring casting speed and length

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.

Describe your application and request an onsite proof-of-concept

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.

Contact us for custom encoder/ sensor configuration

Dear visitor, in order to be able to watch our videos please accept the cookies. All information about the usage of cookies can be found in our privacy policy

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 fieldbus PROFINET protocols

The latest generation of ProSpeed® encoders are laser sensors with compact design and all-in-one integrated optics and electronics. Their enhanced connectivity concept results in a seemless and easy integration into your production line. Use comprehensive accessories for your custom encoder and process control solution. Contact us for free demos and customization by our dedicated PolyXpert service and support team.

Read the application guide of process automation using fieldbus/ PROFINET protocols here or contact us!