Transducers II Flashcards
The impedance of the matching layer is between the impedences of?
the impedance if the skin and crystal
Resonance frequency is also known as?
main frequency, natural frequency, center frequency, operating frequency
What determines the resonance frequency?
the thickness of the crystal and propagation speed
Formula for operating frequency
prop. speed/2xthickness
Thickness of the PZT and frequency are ________ related
inversely
The PZT is _____ of the wavelength
1/2
The speed of the PZT is ______ related to the frequency
directly
What is the purpose to damping?
to shorten pulses; stops extra signals
With damping, SPL will?
decrease (decrease in PD)
With damping, duty factor will?
decrease (less on time)
With damping, Q factor will?
decrease
With damping, sensitivity will?
decrease
With damping, bandwidth will?
increase
Damping limits the SPL to how many cycles per pulse?
2-4
Pulse length and bandwidth are ______ related
inversely
What is bandwidth?
range between high and low frequencies
Fourier Analysis
complex wave forms are broken down into various frequency components
Q factor is determined by?
bandwidth
Imaging transducers require a _____ Q factor
low
The matching layer is _____ the wavelength
1/4
The matching layer is located?
between the crystal and patient
The matching layer is made of?
epoxy and tungsten powder
What is the purpose of the matching layer?
reduce reflectiom
True or False: transducers should be sterilized
False; disinfected
