The major advantages of our Analyzer are as follows:

• high accuracy, repeatability and resolution:

• up to 5 Gaussian distribution components from the analyzed or processed distributions can be determined by our unique program SHAPE™. A chi-square goodness of fit will be computed with each determination.
• smallest samples - 20,000 grains (0.1 gram of fine sand, a few grams of medium to coarse sand); a few multiples of these amounts are needed for repeats and/or documentation;
• many output formats available (our data will never be manipulated by smoothing):
  • our originally measured raw data for processing with our SedVar™ software,
  • files readable by your MS EXCEL2000, MS WinWORD2000 and other standard software;
• speed - depends on the particle sizes in your samples: you may obtain 150 or more analyses within 10 days.

• PSI-sedimentation velocity specified for:
  • laboratory terms (distilled water with various temperature, our gravity acceleration 980.962 gal);
  • standard terms (distilled water at 24°C, gravity acceleration 981.665 gal);
  • local terms (liquid & gravity upon your wish, such as water specified by salinity & temperature, gravity acceleration of the sample's original site);
• PHI-grain size with specified grain shape (Corey's SF);
• Reynolds' number ;
• special variables can be computed for narrow grain size fractions:
  • grain density
  • grain shape

Variable SF' determination.
Having the measured PSI-sedimentation velocity distribution defined mathematically by the parameters of a mixture of up to 5 Gaussian components, our SHAPE™ can match the PSI-values of the distribution to the PHI-values of similarly defined precise sieve grain size distribution: the identical distribution values each identify the values of the PSI-PHI couples. From these couples at 0.02 PSI steps, the SHAPE ™computes to each PSI-PHI couple the pertinent SF'-value. The resulting SF' table can then used by our GRM™ software to analyze the samples of a similar material (with a similar SF'-PSI-PHI relationship) as precision sieving would. A sedimentological interpretation of the SF' distribution should be taken with a great care because it includes both the sieving and MacroGranometer's errors.

Our analyses have been successfully used for unique applications (click).

With our analyses, the following operations  are included:

• producing statistically representative sub-samples on a high quality rotational sample splitter (sized for the MacroGranometer™ input),
• weighing of all sub-samples to milligram (mg),
• storing of unused sub-samples for repeat analyses one year.

Normally, we do not perform any other preparation of your samples for our analysis. Please take care that your representative samples are:

• clean, in appropriately small portions, and weighed.

Clean means that the samples must be free of substances that cannot be analyzed:

• finer particles (clay and silt) - wash them out on a 0.0625 mm (=4 PHI) screen (avoid damaged sieves with enlarged holes)

• coarser particles (gravel) - remove them on a 4 mm (=-2PHI) screen,

• salt & other solubles - washed them out (usually together with the fine particles on the 4-PHI screen),

• organic matter - remove it by boiling in hydrogen peroxide.

Samples in small portions mean that the quantity of your samples should allow us to split them just into about four to ten representative sub-samples.
The following sample sizes of well sorted sands are recommended:

*) Samples with this minimum particle size may be also "poorly sorted": their size is larger  - see below.

Poorly sorted sands (containing both fine and course particles) should be sent in about two to three times larger sample weights.

Please send us your samples
weighed (in grams to two decimal digits) and well identified. Use clearly printed numbers on each bag or sample jar.
We will gladly send you our sample jars in a light-weight polystyrol packaging, each for 20 samples:

Provide us a list of your samples as a table with the following information:

*) DVar = the required distribution variable such as PSI_standard, PSI_local, PHI, etc..

Sample Names 1, 2, and Sample Number are optional. We can include your descriptions (geographic location, borehole identification, depth, core number etc.)  of up to 15 characters each. They will appear in the protocol of each analysis.

Sample weight (to 2 decimal digits of gram). After a brief microscopic evaluation, we'll determine the number of subsamples we will produce from your original sample for our analysis, possible repeats, and documentation (we store the unused subsamples 1 year).

Grain density is usually 2.65 (to 2.70) g/cm³ for quartz and calcite grains.

Shape Factor (defined by A. T. Corey, 1949, and independently by McNown & Malaika, 1950) is usually 0.65. Theoretically, SF of spheres is 1.0. However, sedimentation velocity of smooth spheres provides the values of SF' = 1.18, whereas the SF value of 1.0 corresponds to rough spheres and other isometric particles, including cube.

We recommend to use the SF value 0.65 valid for the most common naturally worn sand particles as a standard instead of the shape of spheres (whether smooth or rough).

Of course, we can compute the results to any grain shape, upon wish.

VISA and MasterCard accepted.

Is your budget stretched to the limit for our instrument this year? Waste neither money nor time by purchasing  an "inexpensive" solution, and do not wait. Use our services now:

• we will perform the analyses for you, and, if you wish, you may apply 50% of the cost of our service up to one year as a down payment toward purchase of your MacroGranometer. Click here to determine your qualification for this option.

Interested in more savings?

• Enjoy a higher quantity discount: increase the number of analyses by combining orders with other co-operating institutions.

• Enjoy our student discount: contact us for details.

Please email   your wishes to  GranoMetry.

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