# The Lawnmowers (Harmonization of Noise Emission Standards) Regulations 1992, Paragraph 3.2: Equivalent continuous sound pressure level LAeq:(t1, t2)


The equivalent continuous sound pressure level LAeq:(t1, t2) is obtained by applying the A-weighting as defined in IEC publication 651, first edition, 1979 to the equivalent continuous sound pressure level Leq:(t1, t2) defined below. This weighting is obtained inter alia by using the A-weighting filter in the measuring system.
The equivalent continuous sound pressure level for a limited period between intervals t1 and t2, Leq:(t1, t2), expressed in decibels, of a noise at a given point is defined by:
where:
p(t) is the instantaneous value of the sound pressure at this point, expressed in Pa;
p0 is the reference sound pressure, equivalent to 20 μPa;
Lp(t) is the sound pressure level at a given time at that point, expressed in dB;
t1 and t2 are the points indicating respectively the beginning and end of the reference period determining the Leq
t1 − t2 is the measurement interval.

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Source: https://www.legislation.gov.uk/uksi/1992/168/schedule/3/part/2/paragraph/3.2 (the official version)
Page: https://openlegislation.uk/lawnmowers-harmonization-of-noise-emission-standards-regulations-1992/schedule-3/part-2/paragraph-3.2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.