Calibration of the TSI 3760 Condensation Nucleus Counter for Nonstandard Operating Conditions

Abstract
The counting efficiency of the TSI 3760 condensation nucleus counter was tested for operation at (a) reduced flow rates and (b)reduced pressures. Circumstances often dictate that these conditions are encountered in sampling atmospheric aerosols. Results indicate that the counting efficiency of the instrument for particles in the range of 0.02–0.1 μm in diameter is not attenuated in operation at flow rates between 0.2 and 1.4 L/min. Furthermore, there does not appear to be any attenuation in the instrument's counting efficiency when operated at pressures between roughly 250 mb and atmospheric pressure.