historyTOSeries   As many of you already know, the EN 13725 was published in February 2022. There are many new provisions in the new text that needs to be reviewed in detail, but maybe one of the most impacting in the day-to-day operations of the over 400 laboratories around the world is the one of the minimal recovery rate accepted for olfactometers.

   With the new standard in hand, no olfactometer can be used for odour measurement under the EN 13725 accreditation scheme, unless recovery rates of 70 % or higher has been tested for four test gases: hydrogen sulphide, n-butanol, propanoic acid and dimethyl sulphide. That means that any olfactometer in the world needs to pass this test if an accreditation is needed. And this is no cheap test.

Weber-Fechner Curve    An Energy Development Facility (EDF) has been evaluated as an odor source to optimize the evaluation of odor persistency. The objectives were to identify the odor characteristics and intensity from the EDF and to determine the relative contribution and variability of the different odors emitted.

   The method includes using the Odor Profile Method to identify each odor character and intensity and using olfactometry as an odor dilution system to determine the persistency of the odor, i.e., the rate of decrease of an odor with dilution. The results showed that air coming from the EDF can pose a rancid and sweet odor nuisance for the community near the EDF and possibly a weak musty odor nuisance for the area further away from the EDF. 

  Hedonic tone Alternative husbandry methods are playing an increasingly important role in terms of animal welfare. In order to ensure that odour pollution from freely ventilated "animal welfare-friendly" fattening pig houses can be adequately taken into account in odour surveys for approval procedures in Germany, the odour annoyance and respectively the hedonic odour effect was investigated in more detail starting from these types of houses.

   The odour annoyance potential of three alternative fattening pig houses was investigated by creating polarity profiles according to guideline VDI 3940 part 4. It was found, that the annoyance potential of those alternative housing forms with natural ventilation and outdoor area as outdoor climate stimulus, as well as bedding (straw), is lower compared to conventional housing forms.

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