Performance of TSI 3760 Condensation Nuclei Counter at Reduced Pressures and Flow Rates

This article describes an experimental study of the performance of the TSI model 3760 clean room condensation nuclei counter (CNC) at various pressures and flow rates. Studies were made to determine the counting efficiency of the instrument in the pressure range of 0.1–1 atm and flow rate range of 0.15–1.4 L/min. The counting efficiency curves were found to be shifted to larger particle sizes as the pressure or flow rate was reduced. The low pressure and low flow rate limits of the instrument were also determined.

The numerical model developed in our previous study (Zhang and Liu, 1990) was used to predict the performance of the CNC. The numerical results were compared with the experimental data and found to agree well in the pressure range of 0.2–1.0 atm and flow rate range of 0.3–1.4 L/min. Discrepancies were found to be more significant at the lower pressures and flow rates.