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NO2 Diffusion Tube Monitoring Calendar

Change Over Dates 2024

Suggested Exposure Periods (2024)
Period Start Date End Date Duration (weeks)
January 3 January 31 January 4
February 31 January 6 March 5
March 6 March 3 April 4
April 3 April 1 May 4
May 1 May 5 June 5
June 5 June 3 July 4
July 3 July 31 July 4
August 31 July 4 September 5
September 4 September 2 October 4
October 2 October 6 November 5
November 6 November 4 December 4
December 4 December 8 January 5

Details

  • The start and end dates of the exposure months are on Wednesdays and exposure periods still consist of 4 or 5 whole weeks, i.e. 28 or 35 days.
  • Tubes should be changed on the specified date. If not tubes may be changed within ±2 days of the due date.
  • The Diffusion Tube Data Processing Tool has been developed to assist local authorities in processing their NO2 diffusion tube monitoring data. The outputs of this tool can be directly uploaded into Diffusion Tube Data Entry System (English non-London local authorities only).
  • The Diffusion Tube Data Processing Tool can accept data from exposure periods other than those above, but data will not be eligible for inclusion in the Air Quality Archive.
  • Please keep a record of site irregularities that may occur in monitoring, for example, building work, changes in traffic flow, etc. This information may be helpful in explaining any unusual results.
  • For a PDF copy of the current calendar, please contact the LAQM Helpdesk.

Change Over Dates 2023

Suggested Exposure Periods (2023)
Period Start Date End Date Duration (weeks)
January 4 January 1 February 4
February 1 February 1 March 4
March 1 March 5 April 5
April 5 April 3 May 4
May 3 May 31 May 4
June 31 May 5 July 5
July 5 July 2 August 4
August 2 August 6 September 5
September 6 September 4 October 4
October 4 October 1 November 4
November 1 November 6 December 5
December 6 December 3 January 4

Details

For older versions of the Diffusion Tube Monitoring Calendar please contact the LAQM Helpdesk for further assistance.

LAQM Helpdesk
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