Abstract: A nebulizer to produce a finely dispersed aerosol from a solution passing over its surface comprises a chamber through which a gas, such as air, is adapted to be blown. The chamber has an outlet conduit, and mounted in the chamber facing the outlet conduit is an inclined upright bar formed with a longitudinal V-groove having a central gas exit port to which is connected a gas input delivery tube. A sample introduction tube is connected to the top end of the bar at said V-groove to admit sample solution thereto. The side walls of the V-groove below the gas exit port are lower in height than above the gas exit port to prevent aerosol droplets from settling on the walls and from interfering with the entry of the aerosol into the exit port. An impactor rod is adjustably mounted on the lower portion of the bar and is adjusted so that its top end is in front of the gas exit port.