Why ultrasound?
Ultrasound vs. alternative sensor technologies
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Ultrasound vs. optical sensors
Optical sensors use light (visible or infrared) to detect objects or determine their distance. Typical applications include position detection of components, surface inspection, distance measurement, and traffic monitoring. Optical sensors work using light barriers, laser triangulation or time-of-flight (LiDAR).
SECO thinks:
Compared to optical sensors, ultrasound is…
Resistant to environmental influences
Reliable measurement even in dust, fog, smoke, or spray, where optical sensors may fail
Independent of surface structure
Glass, transparent or reflective materials cause incorrect measurements in optical sensors.
Regardless of lighting conditions
Optical sensors can be disrupted by sunlight, shading or darkness.
Compact with a large measuring range
Ultrasound can measure short and longer distances without relying on complex optics.
Ultrasonic vs. mechanical sensors
Mechanical sensors operate on the basis of direct physical contact or pressure transmission. Typical applications include level control, position and end position monitoring, and stroke and displacement measurement in industrial plants. Mechanical sensors operate using floats, push buttons, limit switches or cable pull sensors.
SECO thinks:
Compared to mechanical sensors, ultrasound is…
Non-contact measuring method
No physical wear or contamination due to contact with media or objects.
Wear- and maintenance-free
Mechanical systems require regular cleaning and replacement of moving parts.
Flexible for a wide range of media
Ultrasound also works for bulk materials or gases and complex geometries.
Rapid response & high measurement dynamics
Mechanical systems are slower and less precise during rapid movements.
Ultrasonic vs. inductive sensors
Inductive sensors detect metallic objects without contact by changing an electromagnetic field. Typical applications include presence monitoring or position determination in machines or automation systems. Inductive sensors operate using high-frequency magnetic fields that generate field-changing eddy currents.
SECO thinks:
Compared to inductive sensors, ultrasound is…
Independent of the material of the object
Inductive sensors only detect metals. Ultrasound works with liquids, bulk materials, gases, etc.
Durable and contactless
No wear or contamination due to mechanical contact with the object. Maintenance- and wear-free.
Suitable for level measurement
Inductive sensors are unsuitable for non-metallic media. Ultrasound can be used flexibly.
Much larger measuring range
Inductive sensors have a range of only a few millimeters. Ultrasound works reliably over several meters.
Ultrasonic vs. capacitive sensors
Capacitive sensors measure changes in electrical capacity between an electrode and an object or medium. Typical applications include level measurement in tanks and object detection in automation or the packaging industry. Capacitive sensors work by detecting changes in the dielectric constant in the electric field.
SECO thinks:
Compared to capacitive sensors, ultrasound is…
Regardless of the material
Capacitive sensors are sensitive to material properties. Ultrasound measures independently of this.
Resistant to contamination
Ultrasound also works in fog, dust, or dirt. With capacitive sensors, deposits can cause incorrect measurements.
Independent of surface
Capacitive sensors react to the surface area and shape of the object. Ultrasound is less dependent on this.
Larger measuring range
Capacitive sensors are limited to short distances (maximum 50 mm). Ultrasound reaches several meters.
Ultrasonic vs. radar sensors
Radar sensors emit electromagnetic waves (usually in the GHz range) and measure the time or frequency change of the reflected signals. Typical applications include distance measurement in vehicles, level measurement in tanks, and presence detection. Radar sensors operate using time-of-flight measurement or the Doppler effect.
SECO thinks:
Compared to radar sensors, ultrasound is…
Cost-effective
Ultrasonic sensors are significantly cheaper than radar systems due to lower material and energy requirements.
compact design
Radar systems require complex antennas. Ultrasound is less complex and easy to integrate.
precisely at close range
Radar is optimized for long distances, while ultrasound provides precise measurements at short to medium distances.
robust
Radar can be affected by electromagnetic interference and EMC issues. Ultrasound cannot.
Sensor comparison: Why ultrasonic sensors are the best choice for industrial applications
Sensors are essential for automation, robotics, and industrial applications. They detect physical variables such as distance or presence and enable precise control. The most important technologies include optical, mechanical, inductive, capacitive, radar, and ultrasonic sensors. Each technology has specific properties that determine its areas of application.
Optical sensors work with light and offer high precision and fast response times. However, they are highly dependent on environmental conditions and reach their limits in the presence of dust, fog, or transparent objects. Mechanical sensors are robust and inexpensive, but are subject to wear and tear and are not suitable for non-contact applications.
Inductive sensors are reliable for metallic objects, but have a short range and are limited to conductive materials
Capacitive sensors also detect non-metallic materials, but are sensitive to moisture and temperature.
Radar sensors offer long ranges and work in poor visibility conditions, but they are expensive and complex.
Ultrasonic sensors emit sound waves and measure the transit time of the reflected signal. They are material-independent and detect almost all objects, regardless of color or transparency. Their resistance to dust, moisture, and darkness makes them ideal for harsh environments. They are also cost-effective, contactless, and safe for humans. Limitations include a typical range of up to ten meters and a certain sensitivity to temperature changes. Nevertheless, the advantages clearly outweigh the disadvantages: Ultrasonic sensors are versatile, reliable, and economical.
So while optical and radar sensors may be superior in special cases, ultrasound remains the first choice for many industrial applications. If you are looking for a robust, universal, and cost-effective solution, ultrasonic sensor technology is the ideal choice.