AS 1055:2018 pdf free.Acoustics – Description and measurement of environmental noise.
2 The frequency range of the instruments used should also be considered. Typically the range of frequencies should include, as a minimum, the one-third octave bands from 25 Hz to 10 000 lIz. For measurements of low-frequency sound to this Standard, the frequency range should include the one-third octave bands from 12.5 Hz to 10000 Hz. Other frequency ranges may be required by specific Standards or regulatory policy documents.
3 The accuracy of the measurement will depend on the temporal characteristics of the sound being measured and the type of instrumentation being used. Care shoLild be taken to achieve required accuracy in any given circumstances.
4 Methods of determining the time average A-weighted sound pressure level using the various kinds of equipment arc given in Clause 6.4.
5.2 Measurement of time average A-weighted sound pressure level (L.cq.r)
The instrumentation to measure LACq.T shall include but is not limited to
(a) integrating-averaging sound level meter set to frequency-weighting ‘A’; or
(b) data analyser for sampling the running value of A-weighted sound pressure level.
5.3 Measurement of percent exceedance A-weighted sound pressure level (L,%,l)
The instrumentation to measure LAØ..T shall include but is not limited to—
(a) sound level meter set to frequency-weighting ‘A’ and time-weighting ‘F’ with built-in capability for measuring this descriptor; or
(b) data analyser for sampling the running value of A-weighted sound pressure level.
5.4 Measurement of sound exposure level (LAF)
The instrumentation to measure LAE shall include but is not limited to—
(a) integrating-averaging sound level meter set to frequency-weighting ‘A’; or
(b) data analyser for sampling the running value of A-weighted sound pressure level.
5.5 Calibration
The complete measuring system, including portable reference sound sources and any sound recording instruments, shall be calibrated over their full frequency and dynamic range and the configuration for calibration shall be in accordance with AS IEC 61672.1 or IEC 60942, as appropriate. A comprehensive recalibration shall be carried out at intervals not exceeding two years.
5.6 Field checks of calibration
The performance of the instrumentation when in field use shall be checked periodically with a pistonphone, portable reference sound source or other portable checking device appropriate to the sound level meter or other instrumentation system, and immediately before and after measurements are made. For remote logging stations some form of calibration shall be performed at regular intervals. This could be by electronic or acoustic means. For extended measurement periods, these checks shall be performed immediately before and after each measurement sequence. Where the calibration signal cannot be excluded from the data, the instrument shall not be switched off between checks. In all cases, the operating instructions for the instrument shall be followed carefully. If the instrumentation system registers a discrepancy equal to or greater than 1 dB between consecutive checks, any measurements in the interval between the two checks shall be considered invalid.
6 MEASUREMENTS
6.1 General
Details of the measurement instrumentation, measurement procedure, and conditions prevailing during the measurements shall be recorded and kept for reference purposes.AS 1055 pdf download.