DIN ETS 300753:1998-08

The document specifies acoustic noise emission limits for equipment used in telecommunication locations as specified in the ETS 300019-1 series. This ETS covers switching, transmission, power, supervisory, as well tariff and billing equipment. It also specifies methods for measuring, reporting and verifying the noise emission of telecommunications equipment. The details of the methods are found in ISO 7779 and ISO 9296. The descriptor used to quantify acoustic noise emission is the declared A-weighted sound power level in units of bels.