Chapter 8

Question 1

Any device that converts one form of energy into another

Answer 1

Transducer

Question 2

Transmission

Answer 2

Reverse Piezoelectric Effect

Question 3

Reception Piezoelectric

Answer 3

Piezoelectric Effect

Question 4

Electrical energy from the system is converted into sound

Answer 4

Transmission, Reverse Piezoelectric effect

Question 5

The reflected sound pulse is converted into electricity

Answer 5

Reception, Piezoelectric effect

Question 6

Piezoelectric materials change shape when a voltage is applied to them, called

Answer 6

Reverse Piezoelectric effect

Question 7

—– describes the property of certain materials to create a voltage when they are mechanically deformed or when pressure is applied to them.

Answer 7

Piezoelectric effect

Question 8

Piezoelectric is also known as

Answer 8

Ferroelectric

Question 9

Commonly used in clinical transducers

Answer 9

Lead zirconate titanate or PZT

Question 10

Synonyms for PZT

Answer 10

Ceramic, Active element, Crystal

Question 11

Positioned in front of the PZT at the face of the transducer

Answer 11

Matching layer

Question 12

One half wavelength thick

Answer 12

PZT or active element

Question 13

one quarter wavelength thick

Answer 13

Matching layer

Question 14

Increase the efficiency of sound energy transfer between the active element and the body, and protects the PZT

Answer 14

Macthing Layer

Question 15

Crystal damping enhances what

Answer 15

Axial resolution

Question 16

Bonded to the back of the active element, which reduces the ringing of the PZT

Answer 16

Backing Material or Damping Material

Question 17

Backing material is commonly made of what

Answer 17

Epoxy resin impregnated with tungsten filaments

Question 18

What prevents vibrations in the case from inducing an electrical voltage in the PZT of the transducer

Answer 18

Acoustic insulator

Question 19

Damping material do what to the SPL and Pulse duration

Answer 19

Shortens the SPL and Pulse duration

Question 20

What are the characteristics of damping material

Answer 20

1. High degree of sound absorption
2. Acoustic impedance aimilar to PZT

Question 21

3 consequences related to using a backing material

Answer 21

1. decreased sensitivity
2. Wide Bandwidth
3. Low Quality Factor

Question 22

The range of frequency in the pulse

Answer 22

Bandwidth

Question 23

The difference between the highest and lowest frequency.

Answer 23

Bandwidth

Question 24

Transport the voltage from the crystal of the transducer to the system for further processing

Answer 24

Wire

Question 25

The use of gel eliminates the --- layer and facilitates sound transmission into the body

Answer 25

Air PZT-Matching layer-gel-skin

Question 26

Increases the efficiency of the sound energy transfer between the active element and the body and protects the active element

Answer 26

Matching layer

Question 27

The matching layer is ---- wavelength thick

Answer 27

one quarter wavelength thick

Question 28

Bonded to the back of the active element it reduces the ringing of the PZT

Answer 28

Backing Material Damping material

Question 29

Backing material is made of what

Answer 29

Epoxy resin impregnated with tungsten filaments

Question 30

What restricts the extent of PZT deformation

Answer 30

Backing material

Question 31

What will the damping material do?

Answer 31

1. Shortens the spatial pulse length and pulse duration, 2. Improves image quality Short Pulses= higher image quality 3. Decreases the transducer sensitivity

Question 32

What is the relation between Q-factor and bandwidth

Answer 32

Inversely related

Question 33

Formula for Q-factor

Answer 33

Main Frequency / bandwidth

Question 34

Shorter damped pulse has

Answer 34

Lower Q-factor

Question 35

Longer Undamped pulse has

Answer 35

Higher Q-factor

Question 36

A transducer produces a freq equal to its operating freq also called

Answer 36

Resonance Frequency

Question 37

Expose the PZT to strong electrical field while being heated to a substantial temp the process is called

Answer 37

Polarization

Question 38

The sound in PZT and the freq of the sound are

Answer 38

Directly related