Working Principle

• ‌Transducer Vibration‌: When electrical energy is applied, the ceramic transducer vibrates, creating sound waves.
• ‌Wave Propagation‌: These vibrations compress and expand air molecules, forming waves that travel from the sensor’s face to the target object.
• ‌Distance Measurement‌: The sensor emits a sound wave and listens for a set duration to detect the returning echo bounced off the target before retransmitting.

Advantages and Applications

• ‌Reliability in Various Environments‌: Unlike photoelectric sensors, ultrasonic sensors are unaffected by target color or reflectivity, making them reliable in high-glare settings.
• ‌Clear Object and Liquid Level Detection‌: They excel in detecting clear objects and measuring liquid levels.
• ‌Performance in Wet Environments‌: While optical beams may refract off water droplets, ultrasonic sensors function well in wet conditions.

Limitations

• ‌Susceptibility to Temperature and Wind‌: Temperature fluctuations and air currents can affect the speed of sound waves, impacting accuracy.
• ‌Interference from Acoustic Noise and Electromagnetic Devices‌: High-pitched noises and vibrations from electromagnetic devices can interfere with ultrasonic sensors’ performance.
• ‌Warm-Up Drift‌: Temporary inaccuracy may occur during the sensor’s warm-up phase due to temperature fluctuation from a cold start.
• ‌Dead Zone‌: There’s an area directly in front of the transducer where measurements are unreliable due to continued vibrations after the sound wave is sent (phenomenon called ringing).

Considerations for Optimal Use

• ‌Target Characteristics‌: Best targets are large, flat, solid surfaces like metal, ceramic, glass, or wood, placed perpendicular to the sensor.
• ‌Setup‌: Teach the sensor the reflective background surface as the good condition so that any object between the sensor and the background triggers detection.
• ‌Speed Comparison‌: Ultrasonic sensors are slower than optical sensors due to the slower speed of sound compared to light.

Temperature Compensation and Precision

Many ultrasonic sensors, such as Banner’s T30UX Series and QS18U Series, are designed to compensate for temperature fluctuations, ensuring high-accuracy performance across a wide range of ambient temperatures.

Conclusion

Ultrasonic sensors offer a reliable and versatile solution for distance measurement and target detection in diverse industrial applications. Understanding their working principle, advantages, limitations, and considerations for optimal use allows for effective utilization in various environments.