Random Section of GOST 12.1.003-83
1.1 In accordance with the noise spectrum features it shall be divided into:
- broadband continuous spectrum noises extending beyond one octave in range;
- tonal noises, the spectrum of which includes distinct discrete tones. For practical purposes, the tonal feature of noise (while monitoring of noise parameters at workplaces) is determined by measuring in 1/3-octave frequency bands where sound pressure level in one band should exceed the adjacent bands by at least 10 dB.
1.2 In accordance with its time characteristics the noise shall be divided into:
- continuous noise which sound level changes by less than 5 dB A during an eight-hour working day (working shift), when measured at “slow” timing response of the noise dosimeter as per GOST 17187-81;
- non-continuous noises which sound level changes by more than 5 dB A during an eight-hour working day (working shift), when measured at “slow” timing response of the noise dosimeter in accordance with GOST 17187-81;
1.3 The non-continuous noise shall be divided into:
- fluctuating in time noise, which sound level continuously varies in the course of time;
- intermittent noise with sound level that changes in discrete steps (by 5 dB A and more), while the length of intervals during which the level remains stable equals to 1 s and more;
- impulse noise, that comprise one or several sound signals with duration of each less than 1 s, where sound levels differ by at least 7 dB, if measured in dB AI and dB A respectively at “impulse” and “slow” timing responses of a noise dosimeter in accordance with GOST 17187-81.