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Sound Measurement and Analysis
Published in Lewis H. Bell, Douglas H. Bell, Industrial Noise Control, 2017
Lewis H. Bell, Douglas H. Bell
Noise dosimeters are widely used for monitoring noise in workplace environments where sound levels may be hazardous to hearing. Basically, the dosimeter integrates a weighted function of sound pressure or sound pressure level over a time period to determine noise dose, which is a percentage of permissible exposure criteria. Shown in Fig. 5.22 are several dosimeters which are designed for measuring daily noise exposure in accordance with various regulations. Most often these instruments are worn on the person, with the microphone located on the shoulder. When not worn by a person, they may be used as an area monitor.
Hearing, Sound, Noise, and Vibration
Published in R. S. Bridger, Introduction to Human Factors and Ergonomics, 2017
A noise dosimeter integrates the noise measured at the microphone over a period of time and expresses it as a percentage of the daily allowable noise dose (e.g., as a percentage of 90 dB(A) for 8 h). Dosimeters can be used to decide whether workers are being exposed to excessive noise and whether they require ear protection and also to specify for how long per day they may be exposed to a particular noisy work situation (Figure 11.9).
Comparative assessment of shift in hearing threshold among handicraft operatives in India
Published in Ergonomics, 2019
The outlines stipulated in IS 7194:1994 norms for the measurement of sound pressure levels were incorporated and followed with caution during the course of the study. The noise dosimeter (Make: NoisePro DLX□1; ANSI S1.25□1991), which monitors noise levels as dB(A) was used for the measurement of equivalent (Lex, 8 h) and peak (Lpeak) noise exposure. The root mean square measurement range was set to from 70 to 140 dB (A) with a resolution of 0.1 dB increments for F/S response rate. Auto-scaling mode (4 digits) was selected for dose measurement and an exchange rate of 3 dB (A), criterion level at 90 dB (A), criterion time of 8 h, threshold level at 80 dB (A) were set in. Calibration was performed prior to and following each field study using Quest calibrator (3 M Quest QC-10) complying with ANSI S1.40-1984 and IEC 942:1988 Class 1 standards. The 3 M Quest field calibrator device was also recalibrated annually by the manufacturer’s service engineer.