Data Entry System

This system is provided as part of the Defra Local Authority Air Quality Support programme, for the use of UK Local Authorities using NO2 diffusion tubes for Local Air Quality Monitoring purposes.

The Diffusion Tube Data Entry System for England is now available here.

There will be time for all users to review their site information, add new sites, confirm laboratory details and add new monthly data before the data is available for public download.

Previously registered users should receive an email confirming log-in details. If you have not received an email, or are a new user wishing to use the system please contact the LAQM Helpdesk for assistance.

The 2021 Diffusion Tube Monitoring Calendar is now available:

 MonthStart DateDuration (weeks)
2020 November 4 November 4
  December 2 December 5
2021 January 6 January 4
  February 3 February 4
  March 3 March 4
  April 31 March 5
  May 5 May 4
  June 2 June 4
  July 30 June 5
  August 4 August 4
  September 1 September 4
  October 29 September 5
  November 3 November  4
  December 1 December  5
2022 January January -
  • 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.
  • When entering data into the Web Based Data Entry System, please enter the exact exposure dates (on/off) if different from those detailed above by more than ±2days.
  • The Diffusion Tube Data Entry System 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. 


Diffusion Tube Monitoring Calendars can be downloaded below:

back to main Diffusion Tubes pages