Time-of-Flight Stream Counters

Fig ure 6.16. Schematic diagram of the inspection zone of the Amherst Process Instruments Inc. Aerosizer dme-of-flight particle sizer. 

Another aerosol spectrometer is manufactured by TSI Incorporated. Their instrument is known as the Aerodynamic Particle Sizer (APS). This system operates at subsonic flow conditions, and has a lower rate of count than the Aerosizer . The performance of the instrument has been documented in various publications [59, 60, 61]. In 

This required that the two signals be correlated to a start and stop time for every 

With the new equipment it is claimed that both types of errors are eliminated by using overlapping laser beams, producing one double crested beam profile. Each particle then creates a single, continuous signal that has two crests. Particles with only one crest are phantom particles, or with more than two crests are coincident errors and are logged for concentration calculations, but are not used in building the size distribution. The commercial development of aerosol spectrometers is a very active area of research, and one should check for the latest information with the manufacturers of such instruments. 

Hounslow, Coincidence Correction for Electrical-Zone (Coulter Counter) Particle Size Analyzers , Powder TechnoL, 93 (1997) 163—175 Information on the Coulter Counter is available from Coulter Particle Characterization Electronics Inc., R O. Box 169015, M/C 195-10, Miami, Florida, USA, 33116-9015. Information on Celloscope and Electrozone resistazone counters can be obtained from Particle Data, Inc., P. O. Box 265. Elmhurst, Illinois 60126. 

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Time-of-Flight Stream Counters Pin positioned by motor control... 

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