In areas beyond the limits of optical systems, ultrasonic sensors can be used. It can easily detect not only partially and completely transparent or completely dark objects, but also objects such as reflective objects or objects in dust, steam or damp environments. Today, we will share the working principle of ultrasonic sensors.

Working principle of ultrasonic sensor

5SHX06F6004 Ultrasonic sensors work on the principle of sound wave reflection in physics. It works like a radar system, but instead of electromagnetic waves, it uses sound waves with frequencies higher than the range of human hearing (usually above 20kHz, typically around 40kHz). It emits high-frequency ultrasonic pulses (usually in the frequency range of 30kHz to 480kHz) through a built-in piezoelectric ceramic or magnetostrictive material, and these sound waves travel through the air at a constant speed, reflecting off objects and returning to the receiver inside the sensor. According to the arrival time of the echo signal and the known speed of sound, the sensor can accurately calculate the distance and position information of the target object.

Specific process:
1. Launch stage: The sensor first converts electrical energy into high-frequency mechanical vibration, generating and emitting ultrasonic pulses.
2. Propagation stage: These sound waves travel in a straight line at a specific speed in a medium (such as air or liquid) and are reflected when they encounter obstacles.
3. Receiving stage: When the emitted ultrasonic wave encounters the target object and is reflected back, the sensor receives this part of the returned acoustic signal.
4. Processing stage: By calculating the time difference 5SHX06F6004 between ultrasonic transmission and reception, combined with the known speed of sound, the distance between the sensor and the target object can be accurately determined.

Classification and working characteristics of ultrasonic sensors

The working mode of the ultrasonic sensor is divided into three types: diffuse reflection type, reflector type and mirror reflection type

Diffuse ultrasonic sensor/mode of operation

After the sensor is powered on, it will continue to emit ultrasonic waves, and when an object is near, the ultrasonic waves emitted will be returned to the sensor, thus output a response signal.

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5SHX06F6004 Diffuse reflection type ultrasonic sensor/features
• Transmit and receive in one, easy to install
• The object to be measured is equivalent to a reflector and needs to be aligned
• Dual output models have window output function to achieve foreground and background suppression
• Low switching frequency, less than 10Hz, suitable for detecting objects running at a slow speed

Beam type ultrasonic sensor/mode of operation

The beam type sensor is divided into the transmitting end and the receiving end. When the sensor works, the ultrasonic wave emitted by the transmitting end will be received by the receiving end. When an object is near, the ultrasonic wave emitted by the transmitting end will 5SHX06F6004 be blocked, and the receiving end will output a response signal.

Beam type ultrasonic sensor/features
• Transmit and receive separately installed
• Can detect sound sensitive materials or objects with tilted surfaces
• Dual output models have window output function to achieve foreground and background suppression
• No detection blind area, high switching frequency, up to 100Hz, suitable for detecting fast-moving objects

Mirror reflecting ultrasonic sensor/mode of operation

The mirror-reflecting sensor needs to be installed on the opposite side of the reflector, through which the ultrasonic signal is returned for detection. When an object blocks the reflector, the sensor will output a response signal.