# The Lawnmowers (Harmonization of Noise Emission Standards) Regulations 1992, Paragraph 5.5.1: Inspection of the measuring apparatus


Before the tests, the acoustic properties of the entire apparatus (measuring instruments including microphone and cable) shall be checked by means of a calibrated sound source with an accuracy of at least 0.5 dB (e.g. a pistonphone); the apparatus shall be checked again immediately after each series of measurements.

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Source: https://www.legislation.gov.uk/uksi/1992/168/schedule/3/paragraph/5.5.1 (the official version)
Page: https://openlegislation.uk/lawnmowers-harmonization-of-noise-emission-standards-regulations-1992/schedule-3/paragraph-5.5.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.