ISO 1680:2013 音響 — 回転する電気機械から放出される空中騒音を測定するためのテストコード | ページ 5

3.1

time averaged sound pressure level

L_p,T

Note 1 to entry: Because of practical limitations of the measuring instruments, p² is always understood to denote the square of a frequency-weighted and frequency-band-limited sound pressure. If a specific frequency weighting as specified in IEC 61672‑1 and/or specific frequency bands are applied, this should be indicated by appropriate subscripts; e.g. L_{p,A,10 s} denotes the A-weighted time-averaged sound pressure level over 10 s.

3.2

measurement surface

hypothetical surface of area S, enveloping the source on which the measurement points are located

Note 1 to entry: The measurement surface terminates on one or more reflecting planes.

3.3

surface sound pressure level

energy average of the time-averaged sound pressure levels at all the microphone positions on the measurement surface, with the background noise correction K₁ and the environmental correction K₂ applied

Note 1 to entry: It is expressed in decibels.

3.4

sound intensity

time-averaged value of the product of the instantaneous sound pressure and the associated sound velocity at a point in a temporally stationary sound field

3.5

normal sound intensity level

ten times the logarithm to the base 10 of the ratio of the unsigned value of the normal component of the sound intensity (which is radiated by the sound source under test and determined in a direction perpendicular to the measurement surface) to the reference sound intensity

Note 1 to entry: It is expressed in decibels.

Note 2 to entry: The reference sound intensity is 10^–12 Wm^–2.

3.6

sound power level

L_W

Note 1 to entry: If a specific frequency weighting as specified in IEC 61672‑1 and/or specific frequency bands are applied, this should be indicated by appropriate subscripts; e.g. L_W,A denotes the A-weighted sound power level.

Note 2 to entry: This definition is technically in accordance with ISO 80000‑8:2007, 8-23^[15].

3.7

emission sound pressure

p

time-averaged sound pressure, at a 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 from room surfaces other than the plane or planes permitted for the purpose of the test

Note 1 to entry: It is expressed in pascals.

3.8

emission sound pressure level

L_p

ten times the logarithm to the base 10 of the ratio of the square of the emission sound pressure, p²(t), to the square of the reference sound pressure, , measured with a particular time weighting and a particular frequency weighting, selected from those defined in IEC 61672‑1

Note 1 to entry: It is expressed in decibels. The reference sound pressure is 20 µPa.

3.9

noise emission declaration

information on the noise emitted by the machine, given by the manufacturer or supplier in technical documents or other literature concerning noise emission values

Note 1 to entry: The noise emission declaration may take the form of either the declared single-number noise emission value or the declared dual-number noise emission value.

3.10

measured noise emission value

L

A-weighted sound power level, or the A-weighted time-averaged emission sound pressure level, or the C-weighted peak emission sound pressure level, as determined from measurements

Note 1 to entry: Measured values may be determined either from a single machine or from the average of a number of machines, and are not rounded.

3.11

declared single-number noise emission value

L_d

3.12

declared dual-number noise emission value

L and U

measured noise emission value L, and its associated uncertainty U, both rounded to the nearest decibel