Equations Flashcards
RANGE EQUATION
D = RxT
DISTANCE = Rate times time
DEPTH TO REFLECTOR
Depth = Rate x Time/2
FREQUENCY
F=1/P
Number of cycles per second
PERIOD
P=1/F
Time for one cycle to occur
IMPEDANCE
Z=Pc
PULSE REPETITION FREQUENCY
Number of pulses of sound the transducer emits in one second.
PRF=1/PRP
PULSE REPETITION PERIOD
Time from beginning of pulse to the beginning of the next pulse.
PRP=1/PRF
PRP= PD+Idle time
PULSE DURATION
Time that one pulse takes.
PD = # of cycles/f PD= # of cycles x period
The number of cycles in pulse times period.
DUTY FACTOR
Fraction of time the machine is transmitting.
DF=PD/PRP
Pulse duration divided by the pulse repetition period.
SPATIAL PULSE LENGTH
Distance that a pulse occupies.
SPL= # of cycles x wavelength SPL= # of cycles x speed/frequency
INTENSITY
I = P/A
INTENSITY ~ POWER
INTENSITY ~ AMPLITUDE²
POWER ~ AMPLITUDE²
TOTAL ATTENUATION
One-half of the frequency times the path length.
TOTAL ATTENUATION = 1/2f x Path Length
TOTAL ATTENUATION = AC x Path Length
ATTENUATION COEFFICIENT
Amount of energy lost per centimeter of travel.
AC = Frequency/2
HALF-VALUE LAYER
HVL = 3/AC
INCIDENT INTENSITY
Transmitted intensity plus reflected intensity.
Incident intensity = IRC + ITC
INTENSITY REFLECTIVE COEFFICIENT
Reflected intensity divided by incident intensity.
IRC = REFLECTED INTENSITY/ INCIDENT INTENSITY IRC = (Z2-Z1)/(Z2+Z1)²
Medium 2 impedance minus medium 1 impedance divided by medium 2 impedance plus medium 1 impedance, squared
INTENSITY TRANSMISSION COEFFICIENT
ITC = 1 - IRC
One minus the intensity reflective coefficient.
LUEZ’S LAW
Angle of incidence is equal to the angle of reflection.
SNELL’S LAW
SNELL’S LAW =
SINE REFLECTED/SINE INCIDENT) = (SPD MED2/ SPD MED 1
SINE EQUATION
SINE = OPPOSITE/ HYPOTENEUSE
AXIAL RESOLUTION
AXIAL RESOLUTION = SPL/2
LATERAL RESOLUTION
=BEAM DIAMETER
