The main idea of the Field inspections is to estimate the degree of annoyance in a certain problematic area, by means of the olfactory capacities of a group of people or panel members, especially trained and "calibrated" to this effect. The main difference between field inspection and dynamic olfactometry is that in the first case, the panellist are moved to the problematic area to measure the odours on site.

   There is a usual trend for technicians to try to measure odours at ambient air levels. This way of measuring odours has a few advantages:

1) Measuring odours when they produce annoyance, that is, in the receptors. 2) It is less complicated to measure at the fence line or in the receptors that in the stack.
3) In addition it could be carried on as an inspection for compliance procedures.
4) It is a similar approach to that taken for chemical compounds, that can be detected in many cases at ambient air levels.
5) You get instant values instead of averages or percentiles.

    However, there are a few issues to measure odours with these devices.

1) There is no Norm ISO, EN, ASTM, etc that describes the way of working with these devices.
2) There are no studies about precision and uncertainty of these devices, except a few made by the makers.
3) There is no way to validate results.
4) It has to smell on site, if we want to detect anything.
5) Panel members should be calibrated previously with n-butanol and a proper calibration.

Nowadays there are 2 devices available for field olfactometry.

1) Nasal RangerTM
2) Scentroid

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• Combination of techniques and actions for the study and resolution of complex odour issue
• Scentroid reaches a Key Deal with UK distributor