A new commercial instrument for measuring Cloud Condensation Nuclei (CCN), the Droplet Measurement
Technologies Cylindrical Continuous-Flow Streamwise Thermal Gradient CCN Chamber (CFSTGC), installed on
Mount Huang meteorological station (30°19'N, 118°14'E, 1840m above sea level) from 16 April to 28 July 2008. This
instrument can measure CCN concentrations at supersaturations from 0.1% to 2% (potentially up to 6%), as well as a 1
Hz sampling rate that is sufficient for ground-based or airborne platform operation. The instrument records data
continuously at 1-second intervals 24 hours a day. For the 98-day, continuous study the average CCN concentration was
found to range between a few hundred and a few thousand nuclei per cm<sup>3</sup> at supersaturations between 0.3 and 1%.
Diurnal variations were observed, as well as other possible influences, such as wind speed, wind direction and mixing
depth. At a constant supersaturation of 0.5% the CCN concentration is typically on the order of 361 to 2297 nuclei per
cm<sup>3</sup>. A description of the instrumentation and early observations are presented and discussed.