# The Air Quality Regulations 1997, Paragraph 5: Interpretation


A running 8 hour mean is a mean which is calculated on an hourly basis, yielding one running 8 hour mean per hour. The running 8 hour mean for a particular substance at a particular location for a particular hour is the mean of the hourly means for that substance at that location for that hour and the preceding 7 hours.

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Source: https://www.legislation.gov.uk/uksi/1997/3043/schedule/paragraph/5 (the official version)
Page: https://openlegislation.uk/air-quality-regulations-1997/schedule/paragraph-5
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.