Update to diffusion tube database February 2010

Please note that the Nitrogen Dioxide Diffusion Tube Bias Adjustment Factor Spreadsheet has just been updated from the 09/09 version. The new spreadsheet (v. 02/10) may be downloaded from the Review and Assessment website (http://www.uwe.ac.uk/aqm/review/mR&Asupport09.html) and includes the changes detailed in the attached note. The next scheduled update to the bias adjustment spreadsheet is late March 2010. The Diffusion Tube Precision Summary table has also been updated and may be downloaded from the same location as the bias adjustment spreadsheet.

If you haven't already done so, and you now have collocation data available, please fill in the diffusion tube collocation data questionnaire (http://www.uwe.ac.uk/aqm/review/R&Asupport/no2biasquestionnaire2009.xls) and submit it to Kiri Brown [kiribrown@aqconsultants.co.uk].