Ultrasonic sensors

What is an Ultrasonic Sensor and how accurate is it?

Ultrasonic sensors are used for reliable position detection and precise continuous distance measurement of solids, powders and liquids. They transmit and receive sound waves in the ultrasonic range. The object to be detected reflects the sound waves and the distance information is determined via time-of-flight measurement. Blister packages in packaging technology or transparent plastic bowls in the food industry, for example, can be reliably detected.
Even in operating conditions with heavy soiling, dust or mist the sensors detect objects reliably and without interference.
ifm's compact ultrasonic sensors provide a particularly small blind zone, long sensing ranges and a high resolution.
The product range includes units with programmable switching output, analogue output, or a combination of both. Output function, switch points and measuring range are conveniently set via a pushbutton on the unit or via wire teach.
Some sensor types can additionally be configured via IO-Link, e.g. using a USB interface. The moneo software is used to visualise, transfer and archive parameter sets.

How Does the Ultrasonic Sensor Work?

Ultrasonic sensors function by emitting a pulse of sound waves above the human hearing range (usually 20 kHz or higher). The sensor then calculates the time it takes for the sound wave to travel to an object and reflect back. Using the speed of sound, the exact distance to the object can be determined.

For flow measurement, ultrasonic sensors analyze how sound waves behave when moving through a liquid, allowing precise calculations of flow rate. Advanced signal processing ensures accurate readings even in conditions where temperature and pressure fluctuate.

How Accurate Are Ultrasonic Sensors?

Accuracy depends on sensor quality, environmental factors, and the target material. Basic sensors like those used in Arduino projects have an accuracy range of ±3 mm, making them suitable for general distance measurements but not for precise applications.

Industrial ultrasonic sensors, however, offer much higher accuracy, often within millimeter precision. These sensors use temperature compensation, advanced signal filtering, and superior transducer designs to reduce errors caused by air disturbances, humidity, and target inconsistencies.

For applications requiring precise measurements—such as flow monitoring or automated quality control—choosing a high-accuracy ultrasonic sensor is critical.

Ultrasonic Sensor Arduino: How It Differs from Industrial Sensors

For DIY projects, automation prototypes, or educational purposes, ultrasonic sensors for Arduino provide a simple and cost-effective way to measure distances. These sensors, such as the HC-SR04 or JSN-SR04T (waterproof version), are commonly used in robotics, obstacle detection, and basic level measurement.

While Arduino-compatible sensors are great for hobbyists, they lack the precision, durability, and environmental resistance required for demanding industrial applications. Unlike industrial ultrasonic sensors, which provide programmable outputs, robust casing, and temperature compensation, Arduino sensors are limited to simple digital distance readings with moderate accuracy.

How to Connect an Ultrasonic Sensor?

Connecting an ultrasonic sensor depends on the type of sensor being used:

• For Arduino or microcontroller-based projects: Sensors like the HC-SR04 connect via digital input/output pins. The trigger pin sends a pulse, and the echo pin receives the returning signal to measure distance.
• For industrial ultrasonic sensors: These often come with configurable output options (analog, digital, or IO-Link) for seamless integration with automation systems, PLCs, and industrial control networks. Configuration can be done via push-button settings, software interfaces, or direct IO-Link programming.

How to Connect an Ultrasonic Sensor?

Connecting an ultrasonic sensor depends on the type of sensor being used:

• For Arduino or microcontroller-based projects: Sensors like the HC-SR04 connect via digital input/output pins. The trigger pin sends a pulse, and the echo pin receives the returning signal to measure distance.
• For industrial ultrasonic sensors: These often come with configurable output options (analogue, digital, or IO-Link) for seamless integration with automation systems, PLCs, and industrial control networks. Configuration can be done via push-button settings, software interfaces, or direct IO-Link programming.

Ultrasonic Sensor Applications: Where Are They Used?

Ultrasonic sensors have a broad range of applications across different industries. Their ability to detect objects, measure distances, and monitor flow levels without physical contact makes them highly valuable.

Common Applications Include:

✔ Flow Measurement – Used in ultrasonic flow sensors to monitor liquid movement in industrial pipelines.

✔ Level Detection – Monitoring tank levels in industries like water treatment, chemical processing, and food production.

✔ Object Detection & Automation – Ensuring precise positioning and counting in automated manufacturing lines.

✔ Proximity Sensing – Detecting objects in packaging, automotive, and logistics systems.

✔ Obstacle Avoidance in Robotics – Used in autonomous robots and drones for navigation.

✔ Parking Sensors & Vehicle Distance Monitoring – Found in modern cars for parking assistance and collision prevention.

For critical industrial processes, specialised high-performance ultrasonic sensors offer advanced features like temperature compensation, dust resistance, and real-time data feedback.