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New: Molten metal level measurement

New radar solution for level measurement of liquid metal with unprecedented accuracy and reliability

    • Robust radar sensor measures liquid metal at temperatures up to 1600 degrees with high precision and measuring rate
    • Sensor usually does not need to be actively cooled. Optional heavy-duty housing offers additional protection
    • Radar solution enables increased productivity and security through automation of safety-relevant processes

Freiburg, Germany, 1 March 2024 – OndoSense is expanding its portfolio in the metal industry: The German radar specialist has developed a sensor solution for the level measurement of molten metal with unprecedented precision and stability. The robust and low-maintenance radar system reliably measures the level of steel, aluminium or copper at temperatures up to 1600 degrees, even in the presence of dust, fumes, smoke, vibrations or sparks. The sensor usually does not need to be actively cooled, which makes commissioning significantly easier. The solution is based on the OndoSense apex radar sensor and features a measurement accuracy of up to 300 µm, a measurement rate of 300 Hz and a measurement range of 0.1 to 15 meters. As a result, OndoSense offers the most accurate and fastest radar sensor for the level measurement of liquid metal. The OndoSense radar solution not only contributes to increasing productivity and reducing costs, but also makes it possible to automate safety-relevant processes that can pose a risk to operators. In addition, it contributes to lowering CO2 emissions in the metal processing industry.

Minimal maintenance, easy commissioning

Enhanced performance and increased productivity are not the only advantages of the radar system. For instance, the minimal maintenance effort required for radar technology ensures maximum availability: “Radar has no moving parts or sensitive optics. As a result, the longevity of the sensors is very high. In addition, the radar sensor measures faultlessly even when the lens is dirty and only needs to be cleaned very rarely. Temperature fluctuations, metal splashes or reflections have no influence on the level measurement. Our radar sensor technology is easy to integrate and to place into operation. This guarantees an uncomplicated, reliable and highly productive level measurement,” says Mathias Klenner, OndoSense Co-CEO and founder.


Active cooling is usually not required

The sensor solution for molten metal level measurement based on the OndoSense apex radar sensor is suitable for crucibles, ladles and troughs as well as for furnaces or casting molds. As a general rule, active cooling of the level radar is not necessary: “A protective window made of ceramic usually offers sufficient heat protection without affecting the high accuracy and quality of the measurements. For special cases, we have developed an optional heavy-duty housing to shield the sensor electronics against extreme heat,” says Mathias Klenner. With the OndoSense apex radar sensor, OndoSense sets new standards in sensor and measurement technology for the metal industry.

In addition to measuring the level of liquid metal, the range of applications for the sensor includes, among other things, the width and thickness measurement of semi-finished metal products in the rolling mill, the positioning of deslagging machines in batch furnaces and the position control of the steel strip for coating lines or picking system. The OndoSense apex is also suitable for other industries and application areas with adverse production environments – e. g. the mining industry, mechanical and plant engineering or the energy sector.


Highest accuracy and speed – even in harsh environments

Whether dirt, smoke, steam, heat or adverse lighting conditions: Our radar sensor solution offers a measurement accuracy of 300 µm in addition to the high measurement precision of up to 1 µm, even in the extreme conditions of the metal and steel industry. The OndoSense sensor solution thus sets a record in the radar market while at the same time meeting the high requirements of the industry: “Many of our customers in the steel and metal industry not only need very precise measurements, i. e. with values matching as closely as possible in repeated measurements, but also very accurate measurements with the smallest possible deviation between the determined and real measuring values. We are proud to be able to offer our OndoSense apex customers an absolute measurement accuracy of up to 300 µm,” says Axel Hülsmann, OndoSense CTO and founder. You can find more information about the distinction between measurement accuracy and measurement precision in our radar glossary.


Heavy-duty housing to protect against extreme heat

For applications with extreme heat generation, the radar solution features a heavy-duty housing to shield the sensor electronics, if required. The solid stainless steel housing not only ensures passive heat dissipation: If necessary, the radar sensor can also be actively cooled using appropriate connections. The heavy-duty housing has a window that is covered with a heat-resistant ceramic pane. This pane is transparent to radar radiation, so that the radar sensor can be safely placed behind the window. This setup does not affect the high reliability and accuracy of the measurement.


Our solution for molten metal level measurement

  • Highly accurate, reliable and fast level measurement
  • Minimal maintenance with robust radar technology
  • High productivity and easy integration
  • Measurement range: 0.1 to 15 meters

More information:


Product video of OndoSense apex:

More information on OndoSense apex:

More information on radar technology in our radar glossary:


About OndoSense

OndoSense realizes breakthrough radar sensor technology for a digitized industrial world. With sensor solutions based on high-precision, robust radar technology and smart sensor software, we ensure customers get relevant data for the intelligent control of production plants and machines. That way, we are helping to drive digital transformation in the industry. Our innovative, high-performance radar sensors can be used reliably in a wide range of applications - even in challenging environments with dust, steam, smoke, fire or noise. OndoSense was founded in 2018 by two radar experts from the Fraunhofer Institute for Applied Solid State Physics IAF.


Media contact

Michael Teiwes
Head of Marketing & PR
+49 761 79114762

OndoSense GmbH
Bötzinger Str. 60
79111 Freiburg, Germany


Image 1:

Created with GIMP

Caption: Molten steel or aluminium level measurement in the crucible with OndoSense radar sensors – schematic representation. © OndoSense


Image 2:


Caption: The OndoSense apex radar sensor is suitable for high-precision, reliable level measurements, distance and dimension measurements. © OndoSense


Image 3:

Caption: Optional heavy-duty housing that protects the sensor electronics against extreme heat – with and without ceramic protective plate   © OndoSense