Arc welding noise assessment from the measured ultrasound pressure levels. Part II: Pulsed and double pulsed metal active gas welding.

The assessment method of the total and A-weighting-filtered sound pressure levels from the sound pressure levels in selected bands of ultrasonic frequencies, suggested in Part I of this work, was verified on the basis of 226 sets of measurement results of acoustic emission during welding. The pulsed and double pulsed metal active gas welding (MAG-P and MAG-DP) was studied, that constituted a continuation of research on MAG methods. It was shown that the total sound pressure levels due to welding could be reasonably assessed from the sound pressure levels in the octave band with center frequency of 31.5 kHz using a simple empirical equation. The assessment uncertainty was estimated for ±1 dB, which was equal to that attainable in direct measurements with class 1 meter in the field. The assessments of A-weighting-filtered sound pressure levels were based on the measurement results in the 1/3 octave frequency bands with center frequencies of 40 kHz and 20 kHz for MAG-P and MAG-DP weldings, respectively. Although the uncertainty was slightly worse, it was still acceptable taking into account potential practical application of the method: measurements in work environment, especially in places where the acoustic background is not stable. A simple rule for proper selection of the frequency band suitable for this purpose was suggested, refined in comparison with that reported previously.