The NAS-Rack contains an NAIS instrument by Airel Ltd.

The NAIS measures the distribution of ions (charged particles and
cluster ions) in the electric mobility range from 3.2 to 0.0013
cm/V/s and the distribution of aerosol particles in the size range
from 2.0 to 40 nm. The principal components of the instrument are two
parallel electrical mobility analyzers and several software controlled
corona chargers and electric filters. The NAIS has been specifically
designed for atmospheric nanometer aerosol monitoring which is
important in studying new particle formation.