Acestic sensor diaphragm deflection
Acoustic distance sensors, as a rule, work at ultrasound frequencies (40 — 250 kHz). Ultrasonic sensors very well recognize objects that are relatively large compared to the wavelength of ultrasound (~ 1 cm). Ultrasound signals are distributed in the air, so that acoustic sensors cannot be reliable in situations when the air moves at high speed if the air flow cannot be measured and compensated. Acoustic sensors also have difficulties with the implementation of a reliable measurement in an acoustic noisy environment.