Presented are the results of measurements of noise characteristics at working place at the distance of 0.55 m from welding arc using covered electrodes designed for welding carbon and low-alloyed steels. It was established that the equivalent level of sound is 83-86 dBA, and the maximum level does not exceed 93 dBA. It is shown that in welding with covered electrodes the noise level is linearly increased with increase of welding current, here the noise at the working place is mainly contributed by welding process, and the noise from current generator and ventilation equipment is in the ranges of measurements error. The data are given, which can be used for sanitary-hygienic evaluation of noise level at the working place in definite processes of arc welding. 13 Ref., 7 Tables, 1 Figure.

Welding arc is the source of intensive flow of optic radiation in infrared, visible and ultraviolet (UV) ranges, among which the most severe UV-C radiation with a strong harmful effect on the human organs of vision and skin covering should be distinguished. The aim of this work consisted in complex investigation of integral characteristics of UV radiation covered-electrode in manual arc welding (MAW), with covered electrodes of different grades (MR-3, UONI-13/55, ANO-12, ANO-36) and types of coatings (rutile, basic, rutile-cellulose), designed for welding of carbon and low-alloyed steels. The intensity of UV-C and UV-A radiation was measured using dosimeter of optic radiation DAU-81 at the distances of 0.55-1.50 m from the spot of welding. It was established during analysis and statistic processing of measurement results that at this distance at, which usually welder and support personnel are staying during MAW, the integral intensity of UV-C radiation amounts to 0.7-5 W/m 2 , which 700-5000 times exceeds the standard value of 0.001 W/m 2 specified by the acting sanitary standards SN 4557-88 for workers with non-protected skin surfaces. Here the minimum distance, at which staying of the mentioned category of workers at direct visibility of welding place is admissible, amounts from 25 to 65 m (depending on the grade of electrode and value of welding current). Intensity of UV-C radiation depends, in the first turn, on the grade of applied electrodes but not on the type of their coating. It was shown that the intensity of UV radiation is inversely proportional to the square of distance from welding arc and greatly depends on welding current. The results of this work can be used in sanitary-hygienic certification of working stations of welders. 6 Ref., 4 Tables.

The aim of this work was to measure the characteristics of acoustic noise at the workplace during manual TIG welding in argon and semiautomatic welding in Ar + CO2. Welding was carried out inside the welding metal cabin of 1.8 m height, 2.0 m width and 2.4 m depth. The noise parameters were measured using the integrated sound level meter of the first class of accuracy. The point of measurement at the welder's workplace was located at the distance of 0.55 m from welding arc. A single measurement was conducted for about 60 s at the running ventilation unit. It was established that in TIG welding the value of equivalent sound level at the welder's workplace in the wide range of rated values of current I = 45-210 A does not exceed 64 dBA, that is significantly lower than the sanitary-hygienic standard of 80 dBA and is comparable with the level of 57 dBA of the background noise. In semiautomatic welding in Ar + CO2 the noise level at the welder's workplace in the range of rated values of current I = 80-250 A exceeds MAL and reaches 96 dBA. The limit of safe working area as to noise was established at the distance of 2 m from the place of welding. The data of this work can be used for sanitary-hygienic assessment of noise episodes of specific welding processes in shielding gases. 6 Ref. , 3 Tables, 5 Figures. K e y w o r d s :welding in shielding gas, argon, mixture of Ar + CO2, acoustic noise, characteristics

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