[EN 12792:2003, 184]:component intended to even out the velocity and/or to decrease the relative magnitude of the fluctuations characteristic of the air flow and/or to reduce the magnitude of a possible swirl of the air flowExamples of flow equalisers are:air turning vanes inserted in special duct components to decrease the fluctuations characteristic of the air flow and to reduce the nonuniformity of the velocity profile;straightening elements in cross or honeycomb form inserted to eliminate a possible swirl of the air flow;perforated plates, screens or other devices inserted to even out the velocity profile by increasing the pressure loss.