AOS: Dual Column Cloud Condensation Nuclei Counter - aosccn200

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. \n \nARM operates both one- and two-column versions of the CCN.

云凝结核计数器（Cloud Condensation Nuclei Counter，CCN）通过将空气样品通入充满热力学不稳定过饱和水蒸气的柱体，使水蒸气在气溶胶颗粒表面凝结，以此测定气溶胶颗粒的浓度。在此过程中体积增大的活化颗粒将由光学粒子计数器（Optical Particle Counter，OPC）完成计数与粒径测量。借此，云凝结核计数器可将活化后的环境气溶胶颗粒数浓度作为过饱和度的函数进行表征。

大气辐射测量（Atmospheric Radiation Measurement，ARM）项目同时配备单柱与双柱两种版本的云凝结核计数器。