# The Air Quality Standards (Wales) Regulations 2007, Paragraph 1: Group A pollutants (other than benzene and carbon monoxide) and PM2·5


Data-quality objectives are set out in the table and paragraphs below for the required accuracy of assessment methods, of minimum time coverage and of data capture of measurement are laid down to guide quality assurance programmes—
Sulphur dioxide, nitrogen dioxide and oxides of nitrogen
Lead, PM2·5 and PM10
Continuous measurement
Accuracy
15%
25%
Minimum data capture
90%
90%
Indicative measurement
Accuracy
25%
50%
Minimum data capture
90%
90%
Minimum time coverage
14% (one measurement a week at random, evenly distributed over the year, or eight weeks evenly distributed over the year)
14% (one measurement a week at random, evenly distributed over the year, or eight weeks evenly distributed over the year)
Modelling
Accuracy
Hourly averages
50%-60%
Daily averages
50%
Annual averages
30%
50%
Objective estimation
Accuracy
75%
100%

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Source: https://www.legislation.gov.uk/wsi/2007/717/schedule/8/paragraph/1 (the official version)
Page: https://openlegislation.uk/air-quality-standards-wales-regulations-2007/schedule-8/paragraph-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.