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Physics

Acoustic Impedance Matching in Transducers

Quick fact

If a transducer (impedance ~30 MRayl) directly touches air (impedance ~0.0004 MRayl), nearly 99.9% of the sound energy reflects back—none of it enters the body. The gel matches impedances, allowing over 99% of the sound to pass through.

Why this is interesting

Ever wondered why ultrasound technicians apply that cold gel to your skin? It's not just for comfort—without it, most of the sound waves would bounce right off you, creating a blurry image. What's the physics behind this simple trick?

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Acoustic Impedance Matching in Transducers

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