Lesson 3 (Part 1) Flashcards Preview

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Flashcards in Lesson 3 (Part 1) Deck (35)
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1
Q

What does the T/R switch involve? (2)

A
  1. Transmission channel

2. Reception channel

2
Q

What does the T/R switch do? (2)

A
  1. Directs the returning echo voltage from the transducer to the amplifiers during reception
  2. Protects the sensitive inputs from the larger voltages
3
Q

What does T/R prevent?

A

Incorrect direction of a signal

- acts as a traffic cop

4
Q

Which is stronger, the beam going out or coming back?

A

The beam going out

5
Q

What do amplifiers normally receive?

A

A weaker signal

- attenuated

6
Q

What happens if the amplifier receives a stronger voltage from the pulser/pulse delay?

A

The amplifier gets overloaded

7
Q

What does the T/R switch protect?

A

The amplifiers from the outgoing voltage

8
Q

What happens to the voltage at the transducer?

A

The pulse is converted to an electrical signal

9
Q

What gets sent to the amplifier?

A

The electrical signal that was converted from the pulse

10
Q

What does an amplifier do?

A

It increases voltage amplitude

11
Q

Amplification

A

Is the conversion of the smaller voltages received from the transducer elements to larger ones for storage

12
Q

Gain

A

Is the ratio of the output of the amplifier to the electric power input

13
Q

How is power ratio expressed?

A

In decibles

- dB

14
Q

What is the formula for gain?

A

Gain = output power/inputpower

15
Q

What is another term for gain?

A

Power ratio

16
Q

What is power ratio equal to?

A

Power ratio = voltage ratio^2

17
Q

What is amplification the opposite of?

A

Attenuation

  • attenuation = -10
  • amplification = +10
18
Q

What is 3dB equal to in intensity?

A

2x

19
Q

What is 10dB equal to in intensity?

A

10x

20
Q

What is used to counteract attenuation?

A

Amplifiers

21
Q

What are amplifiers involved with?

A

Gain/TGC

22
Q

What does gain control determine?

A

How much amplification is accomplished by the amplifier

23
Q

What happens if you have too little gain?

A

Weak echos are not expressed

24
Q

What happens if you have too much gain?

A

Saturation occurs

- cant get proper readings

25
Q

Why is the gain set?

A

So that echos appear with an appropriate brightness

26
Q

What does each channel have?

A

An amp that amplifies the voltages

27
Q

What can you figure out once you have voltage?

A

Power

- power ratio = voltage ratio^2

28
Q

What do amplifiers allow for? (2)

A
  1. Amplification

2. Compensation

29
Q

TGC

A

Time gain compensation

30
Q

Time gain compensation

A

Equalizes the differences in the received echo amplitude arriving at the transducer if their travel distances are different

31
Q

What is another word for time gain compensation?

A

Depth gain compensation

32
Q

What happens to sound as you travel?

A

It gets weaker

33
Q

What does TGC produce?

A

Uniform brightness throughout the image

34
Q

How is TGC set?

A

By the operator

35
Q

Compensation

A

Amplification at specific depths