An ultrasonic sensor is a device that uses high-frequency sound waves (ultrasound), inaudible to the human ear, to detect the presence, distance, or level of objects or materials.

The sensor has a transducer that acts as both emitter and receiver. It emits an ultrasonic pulse that travels through the air. When this pulse hits an object, it is reflected back to the sensor. The sensor measures the time elapsed between the emission of the pulse and the reception of the echo. Knowing the speed of sound in the medium (usually air), the sensor calculates the distance to the object.

• Non-contact detection: There is no physical contact with the object, which prevents wear and contamination.
• Detection of various materials: Can detect objects of any material (solids, liquids, powders, transparent, colored), regardless of their color, transparency, or sheen, unlike optical sensors.
• Immunity to environmental conditions: They are less affected by dust, smoke, fog, ambient light, and humidity compared to optical sensors.
• Distance and level measurement: Capable of providing precise distance measurement to the target, making them ideal for level applications.
• Versatility: Can be used for presence detection, positioning, and continuous measurement.

• Sensitivity to temperature and pressure: The speed of sound in air varies with temperature, and to a lesser extent, with pressure and humidity, which can affect the accuracy of distance measurement if there is no compensation.
• Dead zone: There is a minimum detection distance close to the sensor where it cannot operate.
• Influence of surfaces: Surfaces that absorb a lot of sound (like wool, foams) or very inclined surfaces can make detection difficult.
• Shock waves and noise: Very loud ambient noise or strong air currents can interfere with measurement.
• Response speed: Generally slower than optical sensors in some high-speed detection applications.

They are widely applied in various industries and scenarios:
• Level Control: Continuous measurement or level detection in tanks of liquids, grains, powders, etc.
• Presence Detection: Packaging, bottles, parts on production lines, even transparent ones.
• Positioning: Object detection on conveyors, positioning of robots and forklifts.
• Diameter/Height Measurement: In rolls of paper, fabrics, or height of material stacks.
• Automotive Industry: Parking sensors.
• Industrial Automation: Automatic gates, security doors, etc.

They can detect a wide range of objects, including:
• Liquids (water, oils, chemicals).
• Solids (metals, plastics, wood, paper, glass, ceramics).
• Transparent materials (PET bottles, plastic films).
• Powdery or granular materials (grains, sand, cement).
• Objects with different colors and textures.

The speed of sound in air increases with temperature. As ECO line sensors do not have integrated temperature compensation, a change in ambient temperature can lead to errors in distance readings.

Yes, ECO line sensors have two potentiometers for adjusting the maximum and minimum distances, which should be set according to the application.

Diffuse sensor: A single ultrasonic transducer is used as both emitter and receiver, mounted in the same housing.
With this type of sensor, the object acts as a reflector of the sound signal. As soon as the object enters the sensor's detection area, its echo causes the output to switch.
The sensors can have two configurable PNP/NPN outputs or one 4-20 mA analog output plus one configurable PNP/NPN digital output.

Since detection is based on sound waves, they are generally immune to electrical noise and EMI, which are more common problems for radio frequency or optical sensors. However, very strong acoustic noise in the environment can, in some cases, interfere with echo detection.