Two points of view. Two ways of seeing calibration of Instrument Odour Monitors (in short here, o-sensors). The 29^th and 30^th of August, the Working Group (WG) 41 committed to the new standard on o-sensors, met in Berlin, Germany to discuss a bit more about the text. This time, there were some very hot discussions on the interesting issue of o-sensor calibration. The tense atmosphere was broken from time to time by the pause for coffees, but all in all, everybody was enjoying the fascinating discussions being hold in the meeting room of the Institute for Materials Research and Testing in Berlin.

   Like in tennis matches, the ball went from one side to the other side of the court. The question is the following: Could a non-specific o-sensor be used on any application? That is, could an o-sensor that is performing fine in a composting site, be used also in an oil refinery? In that case, is there any way to prove that the quality of the results is transferable? should we define procedures to calibrate o-sensors on site? Which is the Certified Reference Material (CRM) to calibrate the o-sensor? is it possible to design a CRM for quality procedures? These and more questions were addressed during these 2-day meetings.

The 13th CEN meeting of Working Group 2 of the Technical Committee 264 'Air quality - Determination of odour concentration by dynamic olfactometry' took place in Berlin (Germany) at the end of August. The day 28^th of August from 09:00 to 17:00 and the 29^th from 09:00 to 13:00 a full review of the text was carried out by 19 experts from a few countries in Europe.

 The Bundesanstalt für Materialforschung und -prüfung (BAM) of Berlin was the place selected for the final review of the future EN 13725. After almost 5 years from the first meeting it is time to sum up the work and approve a final document. The ambitious aim set was to approve each and every of the clauses redacted. Was this goal reached?