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Radar solution for measuring the thickness of steel slabs, flat and long steel – with sub-millimeter precision.

The precise thickness measurement of metal products is essential to achieve reliable product quality at all times in rolling mills and continuous casting plants. Our radar sensor solution determines the thickness and the thickness profile of steel plates, steel strips or steel slabs (up to 1600 °C hot) with an accuracy of up to ±10 µm on the roller conveyor. Thanks to robust radar technology, sophisticated signal processing and intelligent radar algorithms, OndoSense radar sensors achieve this high level of precision in thickness measurement even under the difficult production conditions of the steel industry with smoke, steam, dirt, vibrations, fire and extreme temperatures. Good to know: Material thickness, alloy, metal type (e.g. aluminum, copper, steel, etc.) and metal properties have no influence on the accuracy of the thickness measurement.

This makes the OndoSense radar sensor solution an attractive alternative to radiometric thickness measurement of semi-finished steel products: These measuring systems based on radioactive isotope or X-ray emitters are expensive - both in procurement and in operation. They also require complex radiation protection and intensive maintenance.

Thickness 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 accurate thickness measurement, product tolerance can be reduced: This saves raw material and decreases the rolling mill's CO2 emissions.


Error-free thickness measurement.

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


High productivity, low waste.

  • Optimum product quality thanks to high measurement accuracy: 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 steel thickness measurement

Thickness measurement steel & metal

Measurement accuracy

Sub-millimeter: up to ±10 µm

Measurement range

0.2 to 1.4 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.