Comparison of laboratory measurements of noise from constant voltage and constant current air carbon arcing.
NOISE-CON 2013. The 28th Conference of the Institute of Noise Control Engineering, August 26 - 28, 2013, Denver, Colorado. Washington, DC: The Institute of Noise Control Engineering of the USA, 2013 Aug; :NC13-120
Welders performing air carbon arc cutting and gouging are exposed to sound levels of 108-120 dB(A), reaching hazardous noise exposures in less than three minutes and risking permanent noise-induced hearing loss. To address this issue, the National Institute for Occupational Safety and Health is conducting research to reduce noise emissions from gouging. Experiments were conducted to compare two different electrical operating modes which can be used for the process: constant current (CC) and constant voltage (CV). A-weighted sound power levels and gouge dimensions were measured for each method, as well as current, air pressure, and gouging speed. To reduce variability, gouging was performed using identical steel plates and an automated machine. Common electrode diameters, 1.27-cm (1/2-in) and 0.95-cm (3/8-in), were used. CV produced lower noise emissions in some, but not all, experimental conditions. The noise reductions observed ranged from 0 to 8 dB, and the average noise reduction for CV operation observed across all tests was 3 dB. When both methods were controlled for identical gouge widths, CV yielded 26% deeper gouges than CC. For the parameter settings yielding a noise reduction, CV may be a viable option to reduce worker noise exposure.
Noise; Noise-levels; Noise-measurement; Sound; Hearing; Ears; Permissible-limits; Exposure-assessment; Exposure-levels; Exposure-limits; Noise-induced-hearing-loss; Short-term-exposure; Machine-tools; Laboratory-testing; Exposure-chambers; Air-pressure; Electrical-measurement; Measurement-equipment; Power-generation; Pressure-testing; Machine-operators; Arc-welding; Cutting-tools; Arc-welders; Metalworking
M. Jenae Lowe, National Institute for Occupational Safety and Health, 626 Cochrans Mill Rd, PO Box 18070, Pittsburgh, PA 15236
NOISE-CON 2013. The 28th Conference of the Institute of Noise Control Engineering, August 26 - 28, 2013, Denver, Colorado