Why is representative odour measurement so important?

Did you know that not every odour measurement shows the real odour load?

The first and one of the most important steps in odour load studies at sites is a properly performed odour measurement. A measurement result can only be interpreted and used to prepare decisions if it truly reflects the typical operating condition.

In practice, however, it happens quite often that at the time of sampling the farm or plant is not operating at its usual load.

Common examples are when the livestock building is partly empty at the time of sampling, the technology in use is running at reduced capacity, or extraordinary cleaning was carried out before the measurement.

In such cases the measurement result is valid in itself, but it does not necessarily show the condition that triggers complaints from residents.

What makes a measurement truly representative?

For a reliable odour measurement study it is not enough simply to determine the odour concentration. The measurement report must also include the operating conditions under which sampling took place.

For livestock farms, important information includes, for example:

• the number of animals,

• the age and weight class of the animals,

• the production cycle,

• the operation of the ventilation system,

• feeding and technological conditions.

For industrial facilities, the following are similarly important:

• production volume,

• equipment load,

• material flow,

• operating hours,

• any extraordinary interventions.

These data make it possible for the measurement results to be compared and professionally evaluated later.

It is the conditions that matter, not the season

For odour emission, what counts is not necessarily a given month or a specific period, but examining the less favourable condition that is relevant to odour emission.

In studies it is therefore better to consider measurable meteorological conditions such as the minimum temperature, the daily average temperature or even wind conditions. In many cases a late-spring heatwave can be more suitable for a study than a cool summer week.

The aim, then, is not to pick a calendar date, but to study the period when a relevant condition exists in terms of emission and dispersion.

A good measurement is an excellent basis for expert decisions

In dealing with odour problems at sites, measurement is not an administrative obligation but the starting point of the solution.

Only a representative study backed by proper operating data can show whether intervention is really needed and, if so, exactly where and how it should be carried out.