Sizing Small Sulfuric Acid Particles with an Ultrafine Particle Condensation Nucleus Counter

摘要

The sizing capability of an ultrafine particle condensation nucleus counter (which uses butanol as the condensing fluid) equipped position for sulfuric acid aerosol and sulfuric acid aerosol to which gas-phase ammonia had been added. The response of the counter depended on composition for a range of particle sizes when the water partial pressure was low. For water partial pressures 4 nm in diameter, the response (pulse heights) of the instrument to particles of given size was substantially with ammonia. For water partial pressures > 5 Torr, however, neutralizing the particles with ammonia had little effect on pulse height distributions. For particles samller than 4 nm diameter the pulse heights were insensitive to exposure to ammonia.