Ecma published on 12 December 2024 a new standard that specifies a statistical background correction for information technology and telecommunications equipment noise measurements.
This standard describes a statistical background correction (SBC) for removing background noise contributions from measured noise source levels. Measured source levels include a background contribution because background noise is present during noise source measurement. Since the source is of interest, there is motivation to remove the background contribution. The background must be determined from measured background samples obtained when the source is not operating.
The statistical background correction is an alternative to the legacy background noise correction of ECMA-74 and ISO 7779, ISO 3741, ISO 3744, ISO 3745, and ISO 11201. The SBC can be 2 to 3 dB larger than the legacy correction, with correspondingly lower background corrected source levels, for steady backgrounds near the measured source and precision grade 1 and engineering grade 2 measurements. The SBC avoids the so-called “grade penalty” arising from the different legacy correction values (caps) in the standards, which discourages precision grade measurements by giving an 0.8 dB advantage to engineering grade.
ECMA-425 (Statistical background correction for information technology and telecommunications equipment noise measurements) was developed by Ecma Technical Committee 26 and is available free of charge from the Ecma International website.
Please contact Samina Husain, Secretary General of Ecma International at media@ecma-international.org for any further questions.