Theoretical Simulation and Experimental Characterization of an Expansion-Type Kelvin Spectrometer with Intrinsic Calibration

An expansion-type Kelvin spectrometer has been designed and its performance has been shown to agree with the theoretical simulation within experimental uncertainty. In the intrinsically calibrated mode, number concentration as well as supersaturation can be determined from first principles and experimentally verified. In this mode, the number concentration uncertainty is about ±15%, and the supersaturation uncertainty is about ±20%. The concentration detection limit in this mode depends on the supersaturation and is limited by heat conduction from the walls. In the Mie scattering mode, the detection limit is about 30 cm–3. It is capable of operating in a wide range of supersaturations using a variety of liquids.