BS EN 61689:2013 pdf download

BS EN 61689:2013 pdf download.Ultrasonics – Physiotherapy systems —-Field specifications and methods of measurement in the frequency range 0,5 MHz to 5 MHz.
328
maximum rms acoustic pressure
Pmax
maximum value of the rms acousttc pressure detected by a hydrophone over the entire acoustic field
Note I to entry. Maximum rms acoustic pressure I. expressed In pasca4 (Pa)
3.29
mean square acoustic pressure
mean square of the instantaneous acoustic pressure at a particular point in the acoustic field. The mean is taken over an integral number of acoustic repetition periods
Note I to entry, In practice, the mean value is often derived from ma nleasuren,ents. Note 2 to entry. Mean square acoustic pressure is expressed in pascal squared (Pa2(.
3.30
modulation waveform
temporal envelope waveform of the amplitude modulated wave at the point of peak rms acoustic pressure on the beam alignment axis and displayed over a period sufficiently long to include all significant acoustic information in the amplitude modulated wave
3.31
output power
time-average ultrasonic power emitted by a treatment head of ultrasonic physiotherapy equipment into an approximately free field under specified conditions in a specified medium. preferably in water
Note I to entry. Output power is expressed in wSlt 1W).
[IEC 61161: 2013. definition 3.3. modified — treatment head of ultrasonic physiotherapy equipment instead of ultrasonic transducer)
3.32
peak rms acoustic pressure
maximum value of the rms acoustic pressure over a specified region, line or plane in an acoustic field
Note I to entry. Peak rms acoustic pressure is expressed in pascal (Pa).
3.33
pulse duration
time interval beginning at the first time the pressure amplitude exceeds a reference value and ending at the last time the pressure amplitude returns to that value. The reference value is equal to the sum of the minimum value of the pressure amplitude and 10 % of the difference between the maximum and minimum value of the pressure amplitude
Note I to entry This definition diNers from thet in IEC 62127-1 Amendment 1:2013, from which it is derived, to account for incomplete modulation.
Note 2 to entry. Pulse duration is expressed in second (a).
3.34
pulse repetition period prp
time Interval between equivalent points on successive pulses or tone-bursts
Note I to entry Plus, repetition period is expressed in second (s).
[SOURCE: IEC 62127-1:2007 Amendment 1:2013, definition 3.51. modified – NOTE I from IEC 62127-1 Amendment 1:2013 not copied)
3.35
pulse repetition rate prr
recpiocal of the pulse repetition period
Note I to entry: The pulse repetition rate s equal to the repetition trequency of the modulated waveform.
Note 2 to entry: The pulse repetition rate is espreased in hertz (Hz)
[SOURCE: IEC 62127-1:2007 Amendment 1:2013. defInition 3.52. modIfied — Note ito entry
differs to the original NOTE 1)
3.36
rated output power
maximum output power of the ultrasonic physiotherapy equipment at the rated value of the mains voltage, with control settings configured to deliver maximum output power
Note I io entry. ateO output power is eiipresed in watt tWI
337
rms acoustic pressure
Prms
root-mean-square (rms) of the instantaneous acoustic pressure at a particular point in an acoustic field
Note 1 to enhry: The mean should be taken over an integral number of acouStic repetition periods unless otherwise specshed.
Note 2 to entry: ms acoustic pressure is expressed in pascal (Pa)
[SOURCE: IEC 62127-1:2007 Amendment 1:2013, definition 3.53)
338
spatial-peak temporal-peak acoustic pressure
Psptp
larger of the peak-compressional acoustic pressure or the peak-rarefactional acoustic pressure
Note Ito entry: Sp.atai.peak temporal-peak 5coutic pressure is expressed in pascal (Pa). [SOURCE: IEC 62127-1:2007 Amendment 1:2013, definition 3.63]
3.39
temporal-maximum output power
Pin, in the case of an amplitude modulated wave, the temporal-maximum output power is given by.