Grundlagen der statistischen Partikelgrößenspektrometrie

et al. 2010

Meas. Sci. Technol.

Transmission fluctuation spectrometry (TFS), as a new method of online and real-time particle analysis developed in recent years, can measure the particle size distribution and particle concentration simultaneously. In this work, TFS with band-pass filters is studied by numerical simulation in which the particle concentration varies in a large dynamic range. The results of the simulations show that the transmission fluctuation spectrum is related to the particle concentration of the suspension, the pathlength of the light beam within the particle system and the beam-to-particle diameter ratio. Empirical expressions to correct the effects of particle overlapping on the transmission fluctuation spectrum are obtained, which are found to be experimentally validated.

Section: Formulations Of Tfsmentioning

confidence: 99%

Section: Simulations On the High Concentration Effectsmentioning

confidence: 99%

Section: Simulations On the High Concentration Effectsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Particle analysis on concentrated particle suspensions by transmission fluctuation spectrometry with band-pass filters: part 1. Simulation

et al. 2010

Meas. Sci. Technol.

Particle Size Analysis by Transmission Fluctuation Spectrometry: Experimental Results Obtained with a Gaussian Beam and Analog Signal Processing

Part & Part Syst Charact

2003

Transmission fluctuation spectrometry (TFS) is a method for the analysis of particle size distributions based on the statistical fluctuations of a transmission signal. Complete information on the PSD and particle concentration can be retrieved by a special transformation of the transmission signal, whereby the expectancy of the transmission square (ETS) is determined after the signal has been subjected to a procedure of spatial and temporal averaging. By varying the averaging parameters over a wide range, a spectrum of ETSs is obtained and introduced into a linear equation system, which yields the PSD. In the experimental realization presented here, variable temporal averaging is realized in the frequency domain with a series of low pass filters at different cutoff frequencies while spatial averaging inevitably occurs as the particles pass through a focused Gaussian beam of finite cross section. Experimental results on spherical particles (glass beads) and non‐spherical particles (SiC) are presented. The PSDs are resolved in 30 intervals within a particle size range from 1–1000 μm, employing a modified Chahine inversion algorithm. So far, the measurements are limited to moderate particle concentrations. Some influences affecting the measurements, especially for higher particle concentrations, are discussed in detail.

Transmission Fluctuation Spectrometry with Spatial Correlation

Part & Part Syst Charact

Guo

2005

Transmission fluctuation spectrometry (TFS) is being developed as a new method of particle size analysis. In the early approaches, the particle suspension was illuminated by one beam with finite beam diameter and the transmission signals underwent a process with variable spatial and/or temporal averaging and a subsequent nonlinear operation. The transmission fluctuations were obtained as a spectrum which included the information on particle size distribution and particle concentration.A new approach presented here employs two narrow parallel beams. While changing the beam separation, the transmission fluctuations of these two beams are expressed in terms of the expectancy of the transmission product (ETP). The analytical expression of the ETP through a monolayer is derived and the ETP of a 3‐dimensional suspension is formulated based on the layer model. The deviation between the transition functions of 3‐dimensional suspensions and monolayers is found to be affected by effects from particle overlapping and monolayer structure.