spread (of an air jet in mixing air diffusion)
[EN 12792-2003, 338]:maximum distance (dv) between two vertical planes tangent to a specified isovel and perpendicular to a plane through the centre of the core of an air jet. There may be two different spreads, not always equal: one for the left side, the other for the right side (considered when looking at the treated space from the supply air terminal device)