ISO 11202:2010 音響 — 機械設備から放出される騒音 — おおよその環境補正を適用したワークステーションおよびその他の指定された位置での放出音圧レベルの決定 | ページ 6

3.1

emission

airborne sound radiated by a well-defined noise source (e.g. the machine under test)

Note 1 to entry: Noise emission descriptors can be incorporated into a product label and/or product specification. The basic noise emission descriptors are the sound power level of the source itself and the emission sound pressure levels at a work station and/or at other specified positions (if any) in the vicinity of the source.

3.2

emission sound pressure

p

sound pressure, at a work station or another specified position near a noise source, when the source is in operation under specified operating and mounting conditions on a reflecting plane surface, excluding the effects of background noise as well as the effects of reflections other than those from the plane or planes permitted for the purpose of the test

Note 1 to entry: Emission sound pressure is expressed in pascals.

3.3

emission sound pressure level

L_p

Note 1 to entry: The emission sound pressure level is determined at a work station or another specified position in accordance with either a noise test code for a specific family of machines or, if no noise test code exists, one of the standards of the series ISO 11200 ^[15] to ISO 11205 ^[19] .

3.4

time-averaged emission sound pressure level

L_{p , T}

Note 1 to entry: For simplicity of notation, the subscript T is omitted throughout the following text.

Note 2 to entry: If specific frequency and time weightings as specified in IEC 61672-1 and/or specific frequency bands are applied, this is indicated by appropriate subscripts; e.g. L_{p A} denotes the A-weighted emission sound pressure level.

Note 3 to entry: Equation (2) is equivalent to that for the environmental noise descriptor “equivalent continuous sound pressure level” (ISO 1996-1 ^[1] ). However, the emission quantity defined above is used to characterize the noise emitted by a source under test and assumes that standardized measurement and operating conditions as well as a controlled acoustical environment are used for the measurements.

3.5

peak emission sound pressure

p_peak

greatest absolute emission sound pressure during a stated time interval

Note 1 to entry: Peak sound pressure is expressed in pascals.

Note 2 to entry: A peak sound pressure may arise from a positive or negative sound pressure.

3.6

peak emission sound pressure level

L_{p ,peak}

Note 1 to entry: The peak emission sound pressure level is usually C-weighted and denoted by L_{p C,peak}.

3.7

single event emission sound pressure level

L_E

Note 1 to entry: Equation (4) is equivalent to that for the environmental noise descriptor “sound exposure level” (ISO/TR 25417:2007 ^[21] , 2.7). However, the emission quantity defined above is used to characterize the noise emitted by a source under test and assumes that standardized measurement, mounting and operating conditions as well as a controlled acoustical environment are used for the measurements.

3.8

acoustic free field over a reflecting plane

sound field in a homogeneous, isotropic medium in the half space above an infinite reflecting plane, in the absence of any obstacles

3.9

frequency range of interest

for general purposes, the frequency range of octave bands with nominal mid-band frequencies from 125 Hz to 8 000 Hz or the one-third octave bands with nominal mid-band frequencies from 100 Hz to 10 000 Hz)

Note 1 to entry: Adapted from ISO 6926:1999 ^[10] , 3.10.

Note 2 to entry: For special purposes, the frequency range may be extended or reduced, provided that the test environment and instrument specifications are satisfactory for use over the modified frequency range. Changes to the frequency range of interest should be made clear in the test report. For sources which emit sound at predominantly high or low frequencies, the frequency range of interest should be extended to include these frequencies.

3.10

work station

operator's position

position in the vicinity of the machine under test which is intended for the operator

3.11

operator

individual whose work station is in the vicinity of a machine and who is performing a work task associated with that machine

3.12

specified position

position defined in relation to a machine, including, but not limited to, an operator's position

Note 1 to entry: The position can be a single, fixed point, or a combination of points along a path or on a surface located at a specified distance from the machine, as described in the relevant noise test code, if one exists.

Note 2 to entry: Positions located in the vicinity of a work station, or in the vicinity of an unattended machine, are identified as “bystander positions”.

Note 3 to entry: Throughout the text of this International Standard, the word “work station” applies to any possible specified positions listed in 1.4.

3.13

operational period

interval of time during which a specified process is accomplished by the source under test

3.14

operational cycle

specific sequence of operational periods occurring while the source under test performs a complete work cycle, where each operational period is associated with a specific process that may occur only once, or may be repeated, during the operational cycle

3.15

measurement time interval

portion or a multiple of an operational period or operational cycle of the source under test, for which the time-averaged emission sound pressure level is determined or over which the maximum emission sound pressure level is sought

3.16

time history

continuous recording of the emission sound pressure level, as a function of time, which is obtained during one or more operational periods of an operational cycle

3.17

background noise

noise from all sources other than the source under test

Note 1 to entry: Background noise can include contributions from airborne sound, noise from structure-borne vibration and electrical noise in instrumentation.

3.18

background noise correction

K₁

correction applied to the measured sound pressure levels to account for the influence of background noise

Note 1 to entry: Background noise correction is expressed in decibels.

Note 2 to entry: Background noise correction is frequency dependent. In the case of A-weighting, the correction, K_1A, is determined from A-weighted measured values.

3.19

reference box

hypothetical rectangular parallelepiped terminating on the reflecting plane(s) on which the noise source under test is located, that just encloses the source including all the significant sound-radiating components and any test table on which the source may be mounted

3.20

reference measurement surface

hypothetical surface defined by a rectangular parallelepiped enveloping the noise source under test, terminating on the reflecting plane(s) on which the source is located, and having sides parallel to those of the reference box with each side spaced at equal distance from the corresponding side of the reference box

Note 1 to entry: The “equal distance” is preferably 1 m.

Note 2 to entry: The work station does not have to be located on the reference measurement surface.

3.21

environmental correction

K₂

term to account for the influence of reflected sound on the mean sound pressure level on the reference measurement surface, expressed in decibels

Note 1 to entry:K₂ is frequency dependent and can be determined in accordance with ISO 3744 or ISO 3746. In the case of A-weighting, it is denoted K_2A.

Note 2 to entry: For the purposes of this International Standard, the environmental correction, K₂, is only used as an indicator to qualify the environment and is determined for the reference measurement surface.

3.22

work station directivity index

D_{I ,op}

Note 1 to entry: These levels are determined in an essentially free field over a reflecting plane and have been corrected for background noise and for environmental influences, if relevant.

3.23

apparent work station directivity index

3.24

approximate apparent work station directivity index

3.25

local environmental correction

K₃

correction applied to the measured sound pressure levels at the work station to account for the influence of reflected sound, expressed in decibels

Note 1 to entry: In the case of A-weighting, it is denoted K_3A.

Note 2 to entry: The local environmental correction is frequency dependent.

3.26

typical distance

d

distance from the work station to the closest major sound source of the machine under test, without screening objects protruding into the line of sight between the major sound source and the work station

Note 1 to entry: In the case of extended sound-radiating areas, d is the length of the shortest possible line of sight between the source under test and the work station.