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Width measurement of steel slabs, plates or strips - with sub-millimeter accuracy.

The highly accurate width measurement of semi-finished steel and metal products is of great importance for reliable product quality in the hot rolling mill. With a product tolerance reduced by just a fraction of a millimeter, rolling mills can save significant amounts of raw steel, CO2 emissions and production costs. The OndoSense radar sensor solution determines the width of steel plates, steel strips or steel slabs (up to 1600 °C hot) with an accuracy of up to ±300 µm. Thanks to robust radar technology, sophisticated signal processing and smart radar algorithms, our radar sensors offer this high precision in width measurement even in the extreme production environments of the metal and steel industry with steam, dirt, smoke, fire, vibrations and extreme temperatures. The alloy, metal type (e.g. aluminum, copper, steel, etc.) and metal properties have no influence on the reliability and precision of the width measurement in the rolling mill.

The OndoSense radar sensor solution offers clear advantages compared to radiometric thickness measurement of steel products: On the one hand, these measuring methods based on radioactive isotope or X-ray emitters are very expensive, both in procurement and in operation. On the other hand, these systems require complex radiation protection and are very maintenance-intensive.

Width measurement of steel in the rolling mill

Your added value with radar


Reduced operating costs with radar.

  • Minimal maintenance: Radar has no moving parts, works contactless, requires almost no cleaning and does not need radiation protection.
  • Thanks to precise width measurement, product tolerance can be reduced: This saves raw material and decreases the rolling mill's CO2 emissions.


Error-free thickness measurement.

  • Reliable width measurement even with steam, dust, reflections – regardless of alloy, metal type and metal properties.
  • Reduced scrap and increased product quality because excellent measurement results are available early in the production process.


High productivity, low waste.

  • Optimum product quality thanks to high measurement precision: Product defects are detected early and damage to the rolling system is prevented.
  • Higher productivity through better steel plant utilization as well as avoidance of unplanned downtime and product scrap.

Application data width measurement

Width measurement steel & metal

Measurement accuracy

Sub-millimeter: up to ±300 µm

Measurement range

0.1 to 6 m

Measurement rate

up to 100 Hz

Possible environmental conditions

Water vapour, smoke, dust, dirt, vibration, heat & cold, reflections, difficult lighting conditions

Outputs & interfaces

Analog current loop (4–20 mA), digital switching outputs (3x push-pull), RS485 communication interface, Profinet (via Gateway)

Measured product

Up to 1600 °C hot slabs, steel girders, long and flat steel, steel sheet piling and other semi-finished metal products; measuring accuracy independent of metal type, alloy, material thickness or surface

Suitable radar sensors

OndoSense apex

Radar sensor for distance measurements with the highest precision and speed as well as a narrow opening angle for exact measurement results.

Customers in the metal & steel industry

Your inquiry on our radar sensor solutions.

Please contact us now for advice & quotes.

Do you have questions on our radar sensor solutions and need to discuss your application case with our radar experts? Would you like to order or test our radar sensors for distance measurement or collision avoidance? The OndoSense team will provide you with answers, advise you on the use of radar sensors in your industrial environment and send you a quote.