曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
performed by:
5.4.3 The average EPNL figures obtained by the foregoing
a) computing the arithmetic average for each flight phase process shall be those by which the noise performance of the
using the values from each reference microphone point; aircraft is assessed against the noise certification criteria.
6. NOMENCLATURE: SYMBOLS AND UNITS
Symbol
antilog
C(k)
D
EPNL
Unit
dB
EPNdB
Meaning
Antilogarithm to the base 10.
Tone correction factor The factor to be added to PNL(k) to account for the presence of spectral
irregularities such as tones at the k-th increment of time.
Duration time. The length of the significant noise time history being the time interval between the limits
of t(1) and (2) to the nearest 0.5 second.
Duration correction. The factor to be added to PNLTM to account for the duration of the noise.
Efective perceived noise level. The value of PNL adjusted for both the spectral irregularities and the
duration of the noise. (The unit EPNdB is used instead of the unit dB.)
Frequency. The geometrical mean frequency for the i-th one-third octave band.
Delta-dB. The difference between the original sound pressure level and the f m l broadband sound pressure
level in the i-th one-third octave band at the k-th interval of time.
dB-down. The level to- he subtracted from PNLTM that defmes the duration of the noise.
Relative humidity. The ambient atmospheric relative humidity.
Frequency band index. The numerical indicator that denotes any one of the 24 one-third octave bands
with geometrical mean frequencies from 50 to 10 000 Hz.
Time increment index. The numerical indicator that denotes the number of equal time increments that
have elapsed from a reference zero.
Logarithm to the base 10.
Noy disconlinuily coordinate. The log n value of the intersection point of the straight lines representing
the variation of SPL with log n.
APP 2-16
Appendix 2
Symbol
M(b), M(c), etc.
Annex 16 - Environmental Protection
Unit
-
Meaning
Noy inverse slope. The reciprocals of the slopes of straight lines representing the variation of SPL with
log n.
Perceived noisiness. The perceived noisiness at any instant of time that occurs in a specified fiequency
range.
Perceived noisiness. The perceived noisiness at the k-th instant of time that occurs in the i-th one-third
octave band.
Muximum perceived noisiness. The maximum value of all of the 24 values of n(i] that occurs at the k-th
instant of time.
Total perceived noisiness. The total perceived noisiness at the k-th instant of time calculated &om the
24 instantaneous values of n(i,k).
P@), ~ ( c )e,t c.
PNL
- Noy slope. The slopes of straight lines representing the variation of SPL with log n.
PNdB Perceived noise level. The perceived noise level at any instant of time. (The unit PNdB is used instead
of the unit dB.)
PNdB Perceived noise level. The perceived noise level calculated eom the 24 values of SPL(i,k) at the k-th
increment of time. (The unit PNdB is used instead of the unit dB.)
PNLM PNdB Muximum perceived noise level. The maximum value of PNL(k). (The unit PNdB is used instead of the
unit dB.)
Tone correctedperceived noise level. The value of PNL adjusted for the spectral irregularities that occur
at any instant of time. (The unit TPNdB is used instead of the unit dB.)
PNLT TPNdB
TPNdB Tone corrected perceived noise level. The value of PNL(k) adjusted for the spectral irregularities that
occur at the k-th increment of time. (The unit TPNdB is used instead of the unit dB.)
PNLTM TPNdB Muximum tone corrected perceived noise level. The maximum value of PNLT(k). (The unit TPNdB is
used instead of the unit dB.)
PNLT,.
s(i.4
TPNdB
dB
Tone corrected perceived noise level adjusted for reference conditions.
Slope of soundpressure level. The change in level between adjacent one-third octave band sound pressure
levels at the i-th band for the k-th instant of time.
Change in slope of soundpressure level.
Adjusted slope of soundpressure level. The change in level between adjacent adjusted one-third octave
band sound pressure levels at the i-th band for the k-th instant of time.
q i , k)
SPL
Average slope of sound pressure level.
Soundpressure level. The sound pressure level at any instant of time that occurs in a specified fiequency
range.
Noy discontinuiw coordinate. The SPL value of the intersection point of the straight lines representing
the variation of SPL with log n.
Noy intercept. The intercepts on the SPL-axis of the straight lines representing the variation of SPL with
log n.
Soundpressure level. The sound pressure level at the k-th instant of time that occurs in the i-th one-third
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
附件16--环境保护an16_v1_4ed(58)
