Paragraph 5 InterpretationI1

Northern Ireland Not yet in force

An hourly mean is a mean calculated every hour. The hourly mean for a particular substance at a particular location for a particular hour is the mean of the levels recorded for that substance at that location –

(a)

in the case of benzene, at a frequency of not less than once during the hour; and

(b)

in the case of carbon monoxide, nitrogen dioxide and sulphur dioxide, at a frequency of not less than once every 10 seconds during the hour.

Annotations

Commencement

I1: Sch. para. 5 in operation at 1.9.2003, see reg. 1(1)

Notes on Schedule

Textual amendments

F1: words in Sch. substituted (1.1.2004) by Air Quality (Amendment) Regulations (Northern Ireland) 2003 (S.R. 2003/543), regs. 1, 2

Footnotes

f1

μg/m³: micrograms per cubic metre
ppb/ppm: parts per billion/million
mg/m³: milligrams per cubic metre