Which of the following statements is true concerning vibrating mesh nebulizers?

a. They require at least 3 mL of solution to produce an aerosol.
b. The exit velocity of the aerosol from vi-brating mesh nebulizers is rapid.
c. They add no gas to the aerosol stream.
d. They can produce a particle size range of 1 to 2 ?m.

ANS: C
Vibrating mesh nebulizers add no gas to the aerosol stream. They can generate aerosol from a single drop of liquid, so they require very little solution to produce an aerosol. The exit velocity of the aerosol is slow (less than 4 m/s), and the particle can range from 2 to 5 ?m (mass median aerodynamic diameter).