The invention relates to an atomiser (1) and a housing part (18) detachably connected to said atomiser, each with coding (25, 26). To increase the flexibility in coding using equivalent parts, at least one of the coding means (25, 26) can be mounted in differing, defined positions on the atomiser (1) or detachably to the housing part (18) connected to the atomiser, such that a different coding, in which the coding means (25, 26) match one another, occurs in each position.