Bead
Bubbler
Device -It is also an oldest device for sampling air. It consists of a 250ml suction flask which has an outlet on the side connected to suction pump. A glass bubbler, which is nothing but a glass tube with minute openings at the bottom, is kept in place inside the flask by a rubber stopper. Glass beads of size about 5mm in diameter are kept around the glass bubbler.
In addition the flask contains known volume of broth. Air is drawn into the flask through the glass bubbler when the flask is continuously shaken. The incoming air escapes into the broth in the form of bubbles through the holes at the bottom of glass bubbler.
