Objective Testing
Published: Mon, 06/25/18
Generally, procedures that rely on calibrated equipment and machines, and when exacting techniques and experienced personnel are involved, the objectivity generally goes up.
Let's take sphericity and roundness testing.
This test is where a small split of sand is analyzed under a microscope. A certain number of sand particles are judged based on the shapes of the Krumbein Sloss table. Here, we have a piece of equipment (microscope), but we have the judgment of a technician as to whether or not the sand particle he or she is looking at matches up to a picture on a table.
That's a fairly subjective test.
Now, there is an averaging of results and between technicians which tends to reduce the differences from test to test, and technician to technician. But, nonetheless, the results can vary between technicians. I have done many sphericity and roundness tests, and it is always difficult to judge the roundness (ie the corners) as they relate to the chart.
Now, take the frac sand crush test. Here we use:
* procedures
* machines
* tightly timed test
* experienced technicians
So, as we compare different test procedures, in my opinion, frac sand crush resistance testing is more objective than sphericity and roundness testing. But both tests have their place!
To put us to work on either sphericity and roundness testing, or crush testing on samples you are evaluating for frac sand, visit us!