Test smell from the drain1. smell normal, direct from the sewer.2. sniffing by the biofilter are placed at the drain, then sniffer.3. compare using a minimum of 10 people
Test the smell from the drains first. Sniffer regular direct drain 2. Sniffing a biofilter placed at the drain and smell 3. Compared with at least 10 people.
Test the smell from the drain.1 smell usually directly from the sewer.2. Smell the biofilter placed drain and smell.3. Compared with 10 person is very low.