Instruments
The experimental data of this study have been achieved with
one unit of an integrating and averaging sound level meter with
spectrum analyzer (Bruel & Kjaer Investigator 2260 [16]), one unit
of a noise logging dosimeter (Bruel & Kjaer type 4445 [17]) and one
unit of a sound calibrator (Bruel & Kjaer type 4231).
The configuration of the sound level meter is as follows:
Range – 49.7–129.7 dB.
Bandwidth 1/3 octave.
Peaks over 140 dB.
Global statistics – Fast time weighting and A frequency
weighting.
Spectrum – Fast time weighting and A frequency weighting.
Global measures – A&L frequency weightings.
Logging – 1 record/minute.
The configuration of the dosimeter is as follows:
Range – 70–140 dB.
Time weighting-Fast.
Frequency weighting-A.
Frequency weighting for peaks-C.
Exchange rate-3 dB.
Threshold-75 dB.
Criteria level-85 dB.
Logging-1 record/minute.
Two different softwares have been used for obtaining and processing
the measurements. These are ‘‘Protector” [18] and ‘‘Evaluator”
[19], both by Bruel & Kjaer. ‘‘Protector” is a software package
that has been used for post-processing and archiving noise exposure
data recorded with the dosimeter; it makes the calculations
according to ISO 9612.2. Meanwhile, ‘‘Evaluator” is a software
package that has been used for post-processing, making graphics
and tables and archiving measured levels and spectra taken with
the sound level meter; it has several standards according to which
the calculations can be made, for example ISO1996, DIN45 645, TA
Lärm, NF S 31-010, BS 4142. Both softwares produced the same results
regarding the global levels, with a little tolerance of no more
than 2 dB, after processing the recorded data; so the measurement
procedure and the results of the measurements are validated again
InstrumentsThe experimental data of this study have been achieved withone unit of an integrating and averaging sound level meter withspectrum analyzer (Bruel & Kjaer Investigator 2260 [16]), one unitof a noise logging dosimeter (Bruel & Kjaer type 4445 [17]) and oneunit of a sound calibrator (Bruel & Kjaer type 4231).The configuration of the sound level meter is as follows: Range – 49.7–129.7 dB. Bandwidth 1/3 octave. Peaks over 140 dB. Global statistics – Fast time weighting and A frequencyweighting. Spectrum – Fast time weighting and A frequency weighting. Global measures – A&L frequency weightings. Logging – 1 record/minute.The configuration of the dosimeter is as follows: Range – 70–140 dB. Time weighting-Fast. Frequency weighting-A. Frequency weighting for peaks-C. Exchange rate-3 dB. Threshold-75 dB. Criteria level-85 dB. Logging-1 record/minute.Two different softwares have been used for obtaining and processingthe measurements. These are ‘‘Protector” [18] and ‘‘Evaluator”[19], both by Bruel & Kjaer. ‘‘Protector” is a software packagethat has been used for post-processing and archiving noise exposuredata recorded with the dosimeter; it makes the calculationsaccording to ISO 9612.2. Meanwhile, ‘‘Evaluator” is a softwarepackage that has been used for post-processing, making graphicsand tables and archiving measured levels and spectra taken withthe sound level meter; it has several standards according to whichthe calculations can be made, for example ISO1996, DIN45 645, TALärm, NF S 31-010, BS 4142. Both softwares produced the same resultsregarding the global levels, with a little tolerance of no morethan 2 dB, after processing the recorded data; so the measurementprocedure and the results of the measurements are validated again
การแปล กรุณารอสักครู่..
