Calibration of a Par-Tec 200 laser back-scatter probe FORin situ sizing of fluvial suspended sediment

Abstract

Abstract:The in situ or eective particle size distribution of¯uvial suspended sediment may dier considerably from that of the chemically dispersed mineral fraction owing to¯occulation. Obtaining a meaningful measure of the eective particle size distribution ideally requires that measurements should be made in situ. A rigorous assessment of the associated degree of¯occulation also requires that the same measurement technique is used subsequently to establish the absolute particle size composition of the suspended sediment by analysis of the chemically dispersed mineral fraction. While few in situ measurement devices currently exist, a Par-Tec 200 laser back-scatter probe has previously been shown to be capable of making both in situ and laboratory particle size measurements of¯uvial sediment. The accuracy and precision of this device is assessed in this paper. While able to distinguish relative size dierences with a high degree of precision, the Par-Tec 200 performed poorly in terms of accuracy when compared with measurements made using a laser diraction device. A calibration algorithm has been devised for the Par-Tec 200 size data, using standard sediment samples sized by means of a laser diraction device as the reference. Application of the calibration to Par-Tec 200 measurements of heterogeneous sediment samples signi®cantly improved the representativeness of the particle size distribution, both in terms of overall form, and the median particle size. #

Pickering emulsion prepared by nano-silica particles – A comparative study for exploring the effect of various mechanical methods

“…Interestingly, the measurement size indicated by FBRM varied from that indicated by the optical microscope images under the same conditions. Similar phenomena have been reported by other investigations [32] , [33] , [34] , [35] . FBRM results are compared with alternative particle sizing techniques such as laser diffraction, ultrasonic attenuation spectroscopy, image analysis, and sieving analysis [32] , [33] , [34] , [35] , [36] .…”

“…Similar phenomena have been reported by other investigations [32] , [33] , [34] , [35] . FBRM results are compared with alternative particle sizing techniques such as laser diffraction, ultrasonic attenuation spectroscopy, image analysis, and sieving analysis [32] , [33] , [34] , [35] , [36] . A lot of literature [32] , [33] , [34] , [35] , [36] has reported the phenomena that the FBRM oversized fine particles and undersized coarse ones compared to other particle sizing techniques.…”

“…FBRM results are compared with alternative particle sizing techniques such as laser diffraction, ultrasonic attenuation spectroscopy, image analysis, and sieving analysis [32] , [33] , [34] , [35] , [36] . A lot of literature [32] , [33] , [34] , [35] , [36] has reported the phenomena that the FBRM oversized fine particles and undersized coarse ones compared to other particle sizing techniques. Some RSD values >5% were observed in the appendix, which may be attributed to the inherent flaws of the FBRM technique.…”

Estimating Average Particle Size by Focused Beam Reflectance Measurement (FBRM)

“…FBRM results have been compared with alternative particle sizing techniques (Table 2) for a variety of particle sizes and materials. Early Lasentec FBRM software included a spherical-equivalent size algorithm [14,17,25,27,29,32]. Comparisons between the resulting average size and alternative sizing methods showed that the FBRM oversized small particles (< 150 mm [27], < 300 mm [25]) and undersized larger ones (> 500 mm [25]).…”

Modeling and Experimental Analysis of PSD Measurements through FBRM

“…The results were compared with data using other particle sizers and not always a satisfactory agreement was obtained. Addressing the same problem, Philipps and Walling tried to calibrate FBRM measurements of sus-pended¯uvial sediments using results of a laser diffraction particle sizer [22]. Taddayon and Rohani introduced a two dimensional model approach to transform chord length distributions into particle size distributions for spherical and ellipsoidal particles and compare these results with experiments [23].…”