These micro impingers are designed for sampling of small volumes of air at low jet velocity, as per EPA Method 6. The impinger bottle is graduated from 5 to 30 mL in 5 mL subdivisions. Both the bottle and stopper have 24/40 standard taper joints. The orifice at the impinger tip is 1 mm, passing 0.09 to 0.11 CFM of air at 12 in. H20 vacuum. The top stopper is available with 12/5 ball joints or plain tubulations. The complete set includes the bottle and specified stopper.
For a midget bubbler which is similar but has a extra coarse fritted gas dispersion tube, see item # CG-1821.
Details on EPA Method 6, "Determination Of Sulfur Dioxide Emissions From Stationary Sources" is available from the EPA. Note that the test protocol uses one midget bubbler and 3 midget impingers in series, although substitutions may be made.