Psychometry is a very efficient tool in many cases to deal with the problem of odours in a community. The psychometry is the evaluation of the odour complaints distribution by mean of questionnaires given to the people of neighbouring areas. The statistical analysis of the answers given by the neighbours is an starting point and it can help to design a campaign to measure odours by any other method.

The psychometry can give us answers such as:

• The time-intervals when there is a maximum of complaints.
• The location of the most problematic areas.
• The possible source of the odours.
• The odours with a less accepted hedonic tone by the community..

  The psychometric evaluation is a very effective tool, widely used in many countries (R. Cervinka et al., 2004, E. Gallmann et al., 2004). In Germany there is a norm that specially deals with the psychometric assessment, this is the VDI 3883.

  The Psychometric analysis is quite convenient as a screening study when the purpose is to measure odours by any other method such as field inspections, field olfactometry or dynamic olfactometry + dispersion model, however, this step is often forgotten in many odour studies.

Notes:

In New Zealand there is a very interesting norm based on a Psychometric analysis. + info there. 

   There is increasing interest in the usage of biogas produced from wastewaters, anaerobic digesters and landfill sites as a source of green energy. Biogas generated from these types of sites require process monitoring due to contamination with siloxanes derived from hygiene products, detergent, antifoams, etc. Siloxanes are troublesome impurities in biogases in engine sources.

   The combustion of biogas can lead to deposits of silicon dioxide particles which can cause problems and damage different kind of gas engines or turbines through their build up and via corrosion.The objective of this study was to develop a method on a thermal desorption unit coupled to a gas chromatography and mass spectrometer (TD-GC-MS) to identify and quantify siloxanes present in a representative biogas sample with a low detection limit (µg/m³). Enabling the occurrence of siloxanes in a biogas matrix and efficiency of the removal processes present in the industry to be monitored.