Jornada tècnica sobre olfactometria CEN TC264-WG27 Air Quality - Determination of odour exposure in ambient air by using field inspection

Transcription

1 CEN TC264-WG27 Air Quality - Determination of odour exposure in ambient air by using field inspection

2 Two different methods are suggested: 1.Grid method (long time survey) 2.Two plume methods (short term survey)

3 Common characteristics : Recognition of odour by qualified panel members (humans) The basic result of one measurement is the determination of absence or presence of odours (yes/no) on one point and on a given moment

4 Common objectives Identify in an objective way the odour impact of a given source in the environment Provide a tool-box for verifying the compliance with legal limit values Provide a tool-box for decision makers and authorities if there are complaints Define a method allowing the evaluation of the emissions of a source (non measurable by other methods) by inverse modelling

5 Preliminary remarks: We need first to define an odour hour

6 Concentration Limit of odour detection Mean time 1 hour

7 Definition of one «odour hour» One odour hour is recognized by human nose if odours can be detected during 6 minutes minimum during one hour.

8 2. Two methods for plume inspections One German method derived from the German VDI 3940 Blatt 2 standard, named stationary and one Belgian method (Belgian and from the Netherlands), named dynamic

9 2. Scope of both Plume inspection methods This European Standard describes the Plume Method for determining the extent of detectable and recognisable odours from a specific source using direct observation in the field by human panel members under specific meteorological conditions. With the plume method the presence or absence (YES/NO) of recognisable odours in and around the plume originating from a specific odour emission source, under a specified emission situation and meteorological conditions (specific wind direction, wind speed and boundary layer turbulence) is determined. The unit of measurement is the presence or absence of recognisable odours at a particular downwind location. The extent of the plume is assessed as the transition of absence to presence of recognisable odour.

10 ... The results are typically used to determine a plausible extent of potential exposure to recognisable odours, or to estimate the total emission rate using reverse dispersion modelling. The field of application of this European Standard includes: * The determination of the extent of the recognisable odour plume downwind from a source, under specific meteorological conditions (e.g. wind direction, wind speed, turbulence This European Standard does not include: * the measurement of the frequency of occurrence of odour hours as a representative value for the average meteorology of a location * the measurement of intensity of ambient odours * the measurement of hedonic tone of ambient odours * the calculation of estimated source emission rate from the plume extent using reverse dispersion modelling

11 Stationary method

12 Dynamic method

13 Some results of an evaluation test performed in 2010 by some members of the standardization comity: 1. The stationary method collects information related to the variability of the plume in time 2.The stationary method is very strict and the dynamic method gives more liberty in interpretation of the results 3.The panel members are less influenced by other panelists using the stationary method

14 4. Using a meteorological station is obligatory for verifying the modification of meteorological situation before, during and after the measurement 5. These data are very useful for inverse modelling of emissions of a source. (diffuse emissions, surface emissions, etc.).

15 Example for the importance measuring meteorological conditions: representativity in time:

16 Example for the importance measuring meteorological conditions: representativity in space: : N 2 km Station proche Station à 2 km

17 Merci pour votre attention Contact: W. Kunz KTT-iMA Sarl 20, imp. des Fauvettes F Behren-lès-Forbach