When using two separate search units, one for transmission and one for reception, which pairing is considered most efficient?

When using two separate search units, one for transmission and one for reception, which pairing is considered most efficient?

• A. Quartz transmitter and a barium titanate receiver
• B. Barium titanate transmitter and a lithium sulfate receiver
• C. Lithium sulfate transmitter and a barium titanate receiver
• D. Barium titanate transmitter and a quartz receiver

Answer: (B)

Efficiency comes from two things: making a strong ultrasonic pulse and then catching the echoes with high sensitivity. The transmitter should convert electrical power into sound energy as efficiently as possible, while the receiver should convert the incoming sound back into an electrical signal with high sensitivity. Barium titanate as a transmitter has a high electromechanical coupling, so it can generate a stronger ultrasonic pulse when driven. Lithium sulfate as a receiver offers high sensitivity to the arriving signal, meaning it can detect weaker echoes more effectively. Putting those together gives a strong transmitted wave and a more readily detected echo, making the pair the most efficient option. The other pairings either don’t maximize the initial pulse as well (weaker transmitter) or don’t detect the echoes as effectively (less sensitive receiver), which lowers overall efficiency.

Efficiency comes from two things: making a strong ultrasonic pulse and then catching the echoes with high sensitivity. The transmitter should convert electrical power into sound energy as efficiently as possible, while the receiver should convert the incoming sound back into an electrical signal with high sensitivity.

Barium titanate as a transmitter has a high electromechanical coupling, so it can generate a stronger ultrasonic pulse when driven. Lithium sulfate as a receiver offers high sensitivity to the arriving signal, meaning it can detect weaker echoes more effectively. Putting those together gives a strong transmitted wave and a more readily detected echo, making the pair the most efficient option.

The other pairings either don’t maximize the initial pulse as well (weaker transmitter) or don’t detect the echoes as effectively (less sensitive receiver), which lowers overall efficiency.