Graduated Midget Impinger
This impinger was designed for the sampling of small air volumes with a low jet velocity. It has a similar design to the Greenburg-Smith impinger, except for its smaller size. It requires only a 12" head of water and has a 24/40 Standard Taper joint. Orifice at the bottom of the impinger is 1mm, passing 0.09-0.11 CFM of air at 12" H2O vacuum. Pieces are interchangeable, maintaining nozzle centering and clearance to the bottom inside surface.