Which feature lines the inside of the transducer case with a thin metallic barrier to block spurious signals?

Which feature lines the inside of the transducer case with a thin metallic barrier to block spurious signals?

• A. Case
• B. Electrical shield
• C. Acoustic insulator
• D. PZT

Answer: (B)

The main idea is shielding against electrical interference. Lining the inside of the transducer case with a thin metallic barrier creates an electrical shield that surrounds the sensitive piezoelectric element and is typically grounded. This conductive layer blocks external electric fields and other EMI from reaching the signal path, reducing spurious signals and noise that could distort the received echoes or the transmitted signal. Without this shield, nearby electronics or cabling could couple unwanted signals into the transducer, lowering image quality. Why the other options don’t fit: the case is just the housing and doesn’t specifically block electrical noise; an acoustic insulator affects sound transmission rather than electrical interference; the PZT is the piezoelectric material that converts electrical energy to acoustic energy (and back), not a barrier lining the case.

The main idea is shielding against electrical interference. Lining the inside of the transducer case with a thin metallic barrier creates an electrical shield that surrounds the sensitive piezoelectric element and is typically grounded. This conductive layer blocks external electric fields and other EMI from reaching the signal path, reducing spurious signals and noise that could distort the received echoes or the transmitted signal. Without this shield, nearby electronics or cabling could couple unwanted signals into the transducer, lowering image quality.

Why the other options don’t fit: the case is just the housing and doesn’t specifically block electrical noise; an acoustic insulator affects sound transmission rather than electrical interference; the PZT is the piezoelectric material that converts electrical energy to acoustic energy (and back), not a barrier lining the case.