Evaluation by Hearing Acuity and Some Characteristics of Sound

Investigation on Welding Arc Sound (Report 2)

Abstract

In this paper we describe an experimental study of evaluation by hearing acuity, undesired sound and some characteristics of welding arc sound.
The results obtained are summerized as follows:
1) We can discern the arc voltage difference by hearing of variable welding arc sound within proper arc voltage.
2) NRN of welding arc sound is 78 in CO₂ arc welding and 85 in MIG arc welding of 400A. Then, it is often necessary to protect the organ of hearing from undesired sound of high current welding and impulse welding.
3) Welding arc sound is constituted from wide-band random signal and sine signal of ripple frequency of power source. Intensity of the sine signal emphasized in a Globular and Spray transfer region with increaseing arc voltage.
4) Welding arc sound is remarkably affected by change of droplet transfer and it has the stability in wide region with proper arc voltage. But sound pressure level is the smallest when the arc voltage is larger than proper one.
5) The 707Hz-2245Hz bandwidth is an important frequency region of welding arc sound and in this bandwidth we can get some informations of arc voltage, gas shielding and electrode extension.