29/06/2024 12:30 NO2 Data drops to a negative ~400mg/m3 then see-saws between excessively very hign (~1K) and very low valuies over several days.

02/07/2024 07:00 Settles down without intervention and has been within normal range since.Nothing happening on site that we were aware of during this period, possible roadworks close by? but PM values were normal during this period. Cause for the aberration unknown.

During this period, NOx data should be ignored. PM values were normal during this period