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.