Dayu Electronics: How Loud Is the "Sound" Emitted by a 100KHz Transducer?

During the application and selection process of Dayu Electronics' ultrasonic level meter, customers often raise an interesting question: "How loud is the sound emitted by a 100KHz transducer when it operates? Is it similar to normal human speech?" Behind this question lies a deeper understanding of ultrasonic working principles and the human auditory range. This article will clearly explain this phenomenon from a technical perspective.

First, a core concept needs to be clarified: ultrasound is not an "audible sound." The frequency range of "sound" that the human ear can perceive is typically between 20Hz and 20,000Hz. The ultrasonic transducer operating at 100KHz (i.e., 100,000Hz) is designed to transmit and receive mechanical waves that are far above the upper limit of human hearing, enabling precise non-contact liquid level or solid level measurement. Therefore, its primary transmitted signal—the 100KHz ultrasonic wave—is completely inaudible to the human ear.

Then why do we sometimes perceive a faint "sound" when the equipment is running? This stems from a secondary phenomenon during the circuit drive process. When the drive circuit applies high-frequency electrical pulses to the transducer's piezoelectric crystal, at the instant of pulse excitation, extremely weak mechanical harmonics or circuit transient responses may be generated, with frequencies falling within the audible range. This is the so-called "sound" that the human ear might faintly capture.

The loudness of this audible sound (typically measured in decibels, dB) is not a fixed value. It mainly depends on the driving voltage of the transmitting circuit. The higher the driving voltage, the greater the transient harmonic energy that may be generated, and consequently, the louder the audible sound becomes. Conversely, if the driving voltage is reduced, the sound becomes fainter. Based on actual design and testing, under normal operating conditions, the loudness of this sound is typically controlled between 10dB and 30dB. This is an extremely low sound level, roughly equivalent to a whisper from one meter away or the background noise of a quiet indoor environment—far lower than the volume of normal conversation (about 60dB), and it poses virtually no disturbance to the working environment.

When designing ultrasonic level meters, Dayu Electronics not only pursues excellent measurement accuracy and stability but also fully considers the environmental friendliness of the equipment. Through optimized circuit design, precision transducer manufacturing, and rigorous drive control, we ensure that the equipment efficiently completes ranging tasks while minimizing any subtle sound generated during operation to extremely low levels, meeting the requirements of various industrial and commercial applications that demand high silence.

We hope the above explanation helps you gain a more comprehensive understanding of our products. Dayu Electronics is always committed to providing customers with reliable and quiet ultrasonic measurement solutions through professional and rigorous technology.