title: The Doser external counting device.
authors.forename: D M
authors.initials: DM
authors.lastname: Williams
authors.forename: A
authors.initials: A
authors.lastname: Wessell
authors.forename: T P
authors.initials: TP
authors.lastname: Brock
mesh_terms: D000280:Administration, Inhalation; D016503:Drug Delivery Systems / Q000295:instrumentation*; D006801:Humans; D009330:Nebulizers and Vaporizers; D015203:Reproducibility of Results