To collect an air sample, the canister is put under vacuum by sucking out all the air with a pump. The valve of the canister can then be opened in the field, which causes the canister to fill with the (ambient) air to be sampled. A major advantage of this technique over the sampling bags is the shelf life of the sample, which ensures that the samples do not have to be presented to the lab within 24 hours.
SAMPLING DURING SPECIFIC PERIODS (MONITORING)
To take an air sample over a longer period, for example 8 hours in the context of exposure, a flow regulator can be mounted on the canister. In the OLFASCAN lab, this is configured so that the desired sampling time is achieved. Currently, OLFASCAN has the option to take samples for 0.5 hours up to 48 hours.
When an odour only occurs sporadically, or under specific circumstances, it is often difficult to schedule a sampling by an OLFASCAN technician. Because of the very simple operation and flexibility, it is possible to take air samples yourself with canisters.