Abstract: A field olfactometer includes a mixing chamber connected to a mask. A sample flow path is defined through the olfactometer as is a diluent flow path. The sample flow path extends from a sample air inlet to a sample air outlet which is open to the mixing chamber. The diluent flow path extends from a diluent air inlet to a diluent air outlet which is also open to the mixing chamber. The sample flow path and diluent flow path are isolated from one another so that the sample air flowing through the sample flow path and diluent air flowing through the diluent flow path cannot mix until the two streams of air exit their respective flow path and enter the mixing chamber where the two streams mix thoroughly prior to reaching the mask. The diluent flow path includes a filter medium to remove odor-causing chemicals from ambient air drawn through the diluent flow path.