aosccn100 (01)

The cloud condensation nuclei counter measures the concentration of aerosol particles by drawing an air sample through a column with thermodynamically unstable supersaturated water vapor that can condense onto aerosol particles. Particles that are activated, i.e., grown larger in the process, are counted and sized by an optical particle counter (OPC). In this way the CCN measures activated ambient aerosol particle number concentration as a function of supersaturation. ARM operates both one- and two-column versions of the CCN.

云凝结核计数器（cloud condensation nuclei counter）通过将空气样本抽入含有热力学不稳定过饱和水蒸气的柱体来测量气溶胶粒子（aerosol particles）的浓度，这些水蒸气可在气溶胶粒子上凝结。活化的粒子（即在该过程中长大的粒子）由光学粒子计数器（optical particle counter，OPC）进行计数和尺寸测量。通过这种方式，CCN可测量活化的环境气溶胶粒子数浓度随过饱和度变化的函数关系。ARM运行CCN的单柱和双柱版本。