EN13725 standard

Assessor

The terms ‘assessor’ and ‘panel member’ are used in the EN13725.  An assessor is a person who participates in odour measurements.  A panel member is an assessor who is qualified…

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CEN Standards

See EN13725 standard Standard on Determination of Odour Concentration by Dynamic Olfactometry  

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Detection threshold (DT)

Detection threshold is essentially the minimum amount of odorant that can be perceived (smelled).  This minimum amount represents the odour concentration and is a measurement of 1 OU (1 odour…

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Dilution factor

A ratio of diluting neutral gas to odourous sample gas.  According to ASTM E679, this is a ratio of diluting gas to the odour sample.  According to the EN13725, this…

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Direct Olfactometry

Measurement of odour without a time lag between sampling and analysis. The time lag between sampling and analysis according to the EN 13725 is 30hours and according to the VDI…

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EN 13725 – YES/NO Mode

The assessor is asked to evaluate gas presented from a specific port and to indicate if an odour is perceived ( YES/NO). The assessor is aware that in some cases…

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EN 13725 – Forced Choice Mode

The assessor is presented with two or more ports, of which one presents the stimulus and the other(s) neutral gas.The location of the stimulus in consecutive presentation is randomly distributed…

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EN13725

In Europe, dynamic olfactometry, is described in detail by the European standard EN 13725. This standard was last released in 2003 and is currently under review for revision. Key elements of…

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Federal Clean Air Act (FCAA)

A federal law passed in 1970 and amended in 1974, 1977 and 1990 which forms the basis for the national air pollution control effort. Basic elements of the act include…

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Habituation

The inability or decreased ability to perceive an odour as continued exposure to that odour increases over time.  An odour may initially be strongly detectable but may diminishes completely in…

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