Advanced Sand Sedimentation
Analyzer:

MacroGranometer™ is a computerized sedimentation analyzer of waterinsoluble, sandsized material, using gravity sedimentation from a single level (stratified sedimentation) in water. Employing the most sophisticated solutions makes it the unique tool for sand sedimentology, which provides high quality and meaningful results, with added operational and maintenance ease, and a variety of outputs.
MacroGranometer™ measures the sedimentation velocity distribution, and its data processing program, SedVar™, converts it into a distribution of other sedimentation variables, such as shapespecified grain size. For the conversion, the equation for drag coefficient as a function of Reynolds' number and grain shape developed by J. Brezina (1979b) is utilized.
Distributions of the following sedimentation variables are available:
 sedimentation velocity, in three versions:
 laboratory
 standard
 local
 shapespecified grain size
 grain shape
 grain density
 Reynolds' number
The grain parameters density and shape can each be quantified as a distribution. This is possible from samples of nearly equal grain size such as narrow sieve fractions.
Our processing software SedVar^{™} also computes distributions of the grain sedimentational Reynolds' number; these distributions, similarly to those of PSI sedimentation velocity, feature a less negative skewness than the pertinent PHI grain size distributions. In fact, the skewness of the grain sedimentational Reynolds' number distributions has a medium value between the most negatively skewed PHI, and least negatively skewed PSI distributions). Not only that our Reynolds' number distributions use the shapespecified grain size but can be computed for samples of nearly equal grain size (narrow sieve fractions with varying grain density), and for nearly equal grain density.
The MacroGranometer^{™} system is shown on the schematic view below:
3a
GRM™, Measuring & Operational Software
example of the GRM™ analysis window(User's 486 66 MHz DX2 PC or higher, with 1 LPT and 1 COM interfaces)
2
Control & Measuring Electronic Box
CFM automatic digital amplifier, control & sensor PCBs,
power supply, cable distributor3b
SedVar™, Processing SoftwareThe schematic view of the MacroGranometer™
the sedimentation length L is usually 180 cm
3D view of the Upper Part of the Sedimentation Tube: Venetian Blind (sample introduction)
3D view of the MacroGranometer's™ Sedimentation Tube (larger view: klick)
Open lamellae of the Venetian Blind (without rotational magnet etc.)
Underwater Balance Body (larger view: klick)
3DView of the Underwater Balance Body
3D view of the Lower Part of the Sedimentation Tube with the Underwater Balance (larger view: klick)
Our measuring software GRM^{™} runs on the user's 486 DX2 66 MHz PC or higher, under MS DOS 6.2 or higher. It controls the system's operation and stores the measured data as ASCII files.
Our processing software SedVar^{™} runs on the user's MS Windows 98 PC or higher. It processes the measured PSI local sedimentation velocity distributions. SedVar™ consists of three parts:
 SedVar™, distribution conversion,
 SedGraph™, graphical output generator,
 Sed 3D Graph™, 3D plot of a multiple distribution graph.
MEASURING RANGE: 0.016  4 mm quartz density materials: 0.044  4 mm heavier materials: may be finer, such as 0.016  1 mm; SAMPLE SIZE: smallest, statistically representative samples of
15,000  20,000 grains (0.1  5 gram);settling rate resolution: 0.02 PSI weight resolution: 0.01 %
RESULTS: semi graphic and full graphic printouts showing distributions of the six sedimentation variables listed above, such as laboratory, standard and local PSI sedimentation velocities, PHI grain size, density, shape factor and Reynolds' number including either variable size, density or shape factor. The standard sedimentation velocity and Reynolds' number are available also for sieve fractions (constant size) and heavy liquid fractions (constant size and density); each variable is resolved into 401 logarithmically equidistant intervals.
Mean, spread, asymmetry & peakedness are calculated as moment and percentile distribution characteristics of each variable. Other characteristics may be included as you wish.
The program Sed 3D Graph™ (part of the SedVar™ program) permits a graphical display of a group of distributions, either according to the samples' geographic horizontal or vertical location, or according to another desired variable. For example, a group of PSIsettling velocity (or grain density) distributions, each from a constant grain size fraction, can be plotted according to their PHIgrain size.
The optional program SHAPE™ provides the possibility of separating as many as five mixed distribution components, each normally distributed. This program can match a sieve analysis to the sedimentation analysis of the same sample, and compute Shape Factor values to each 0.02PSI sedimentation velocity. Our SedVar™ program can use this set of the variable SF values to adjust the sedimentation grain size distributions of similar samples (the results of the MacroGranometer™) to the sieving; in other words, it can simulate the sieving errors.
Department of Geological Sciences, University of Trieste, Italy (click);
Department of Geology, University of Vienna, Austria (click).
Example of a PSI distribution decomposed into Gaussian components
SAMPLE:
FileName:
sed122.dat
A sand
fraction, consisting of nearly monosize grains, made by precision sieves with
circular holes:
Material: 
black sand 
sample 13 
at a 90° intersection of beaches 
Locality: 
near Casusay 
Venezuela Bay 
about 110 km NNW of Maracaibo 
Sampling Date: 
1972515 
low tide 
tide amplitude: about 75 cm 
Analysis date, time: 
198121, 16:55h 
T_{mean}
= 24.76°C 

Preparation: 
precision wet vibration sieving 
circular holes ± 0,002 mm 

MonoSize: 
1.770 ±0.0639 PHI 
= 0.297 ±0.013 mm 

Average of 8 sample 
Total Mass: 
0.6916 gram
0.08645 gram 
SF = 0.63 (calculated Corey‘s Shape Factor)
G_{lab} = 980.962 gal (cm/sec^{2}) 
PSI Distribution of MonoSize (1.77PHI=0.297mm) Polymineral Fraction Decomposed into 4 Gaussian Components
Our Sand Sedimentation Analyzer™
(MacroGranometer™)
measured at 0.02 PSI intervals (Xaxis).
No data manipulation such as “smoothing“ has been used.
The smoothness
of the 1st derivative,“Input d%“, shows the
analysis quality.
Our Program SHAPE™
identified
4 Gaussian Components (Comp
1,
Comp 2,
Comp 3
and Comp 4).
Our
Program SHAPE™
(based on the method by Isobel CLARK,
1977)
decomposed
the analyzed
PSI
distribution into
4
Gaussian
components
with the following 11
parameters

4 means, 4 standard deviations, 3 percentages
(the 4th one is the rest up to 100%):
# 
PSImean 
St. Dev. 
% 
Density 
Minerals
(calculated & confirmed) 
1 
2.8095 
.1007 
34.56 
4.76 
ilmenite 
2 
2.6376 
.1645 
52.15 
4.16 
garnets 
3 
1.9685 
.1090 
9.90 
2.65 
quartz,
feldspars, calcite 
4 
1.5137 
.2601 
3.39 
2.08 
porous
calcite (fossils) 
Goodness of fit 
ChiSquare: 
χ^{2} <0.01 
Our Program
NGRM™
calculated density from the constant PHI size and each PSImean value.
The density
values of each component match the minerals identified microscopically and by
Xray diffraction analysis.
Our Program SedVar™ converted the variable PSI into
a log
density distribution (not shown here).
The client should build and fix two steel Bases to carry both the Air Shock Absorbers, and an operation platform before our installation. Also, a container with about 100 liter distilled water should be available a few days before our installation (the container should be positioned above the top of the sedimentation column in order its water will be warmer, and without dissolved air).
J. Brezina collected and processed the data of the Experiment from 17 participants, however, he did not complete the final processing before the publication deadline of the book by J. P. M. Syvitski (click on the author's review of the Syvitski's book in Basin Research 4/1992).
Below are shown the calibration results of one of the MacroGranometer™ users, the participant No. 14 (in the Syvitski's book quoted under instrument code ST3), in comparison with a precision 0.25PHI sieving, made by participant No. 7.
The calibration samples consisted of glass spheres with exactly determined density of each of the five mixture components; three sand samples were mixtures of up to three components. J. Brezina produced each mixture component on 65millimeter screens featuring galvanically deposited meshes with circular holes, with the aid of random vibration of the glass spheres in alcohol suspension on each screen. The minimum material on each screen enabled that only onelayer of spheres has been screened until constant amount of retained spheres (zero throuput), which resulted into ample sieving time.
The component portions have been obtained on a high precision rotational sample splitter using the slowest possible samples' flow. The high statistical representativity of each split was confirmed by the negligible variation of the weight of each component split. Still, each sample had a specific percentage of the three components, and, this way, has been produced exclusively for each participant.
The percentages of each three sieve fractions of the Sand 1 are shown in the Table below, column headed by "14" for the Participant 14 (Syvitski's code "ST3"), who analyzed the subsample [split] 4, = "14S1S4") by the MacroGranometer. This subsample had a mean density 2.487125 g/cm^{3}.
For comparison, three sieve fraction percentages of the Sand 1 are shown in the same Table, column headed by "7" for the Participant 7, who analyzed the subsample 2 by a carefully executed sieving at 0.25 PHI.
Participant#  14  7  
#  PHImean  mm  g/cm^{3}  %  % 
1  0.515±0.010  0.700±0.005  2.5050  25.3  26.0 
2  1.000±0.015  0.500±0.005  2.5035  20.7  20.6 
3  1.498±0.020  0.354±0.005  2.4700  54.0  53.4 
The MacroGranometer™ analysis by the participant 14 of the same sample, and decomposed by our program Shape™ have recovered the original three distribution components very closely:
#  PHImean  mmmean 
PHIstandard deviation 
% 
1 
0.5840 
0.667  0.0698  22.39 
2  0.8733  0.546  0.0842  26.99 
3  1.4926  0.355  0.1053  50.63 
Below are the graphical plots of the MacroGranometer™ analysis (participant 14, sand 1, subsample 4 = 14S1S4.dat):
Example of an analysis processed by SedVar™
into
frequency and cumulative curves
(the frequencies are plot in linear scales).
The sample 14S1S4 was a calibration material consisting of glass
spheres, participant 14 ("ST3"), sand 1, subsample (split) 4.
Example of an analysis processed by SedVar™
into cumulative curve
(the cumulative frequency is in probability scale).
The same sample as above.
Below is the graphical output of our SHAPE™ program (produced by MS EXCEL program):
Below is the result of standard sieving (at 0.25 PHI intervals) by the participant 7.
The histogram above suffers from three fundamental shortcomings of the sieving (at 0.25 PHI) in comparison with a sedimentation method (at 0.02 PHI):
Please note that Syvitski has not:
exactly known the size distributions of the test samples synthesized by J. Brezina, therefore his evaluations could not be appropriate;
identified the mixed distribution components by a program such as our Shape™.
Five types of settling tubes provided clearly better results than all other tested instruments (image analyzer, CoulterCounter™, Malvern™ laser particle sizer, SediGraph™, photosedimentometer Lumosed™).
From the five settling tubes, three ones (two of them were MacroGranometers™) qualified as Advanced Settling Tubes. The output of both MacroGranometers™ best matched the expected results using the above shown highly demanding criteria (fit of the mixed distribution components).
The other settling tubes, and particularly other instruments, could even not reproduce the original fractions. The component modes were so strongly shifted that they could hardly be recognized as formed by the original fractions; frequently, additional modes formed or some of the modes disappeared.
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