Abrasion by Falling Sand

Abrasion Testing Procedure

1. Assemble the apparatus so that the sample holder is directly in-line with the sand tube and funnel, and so that the large collection bin is able to trap all used sand.
2. Choose sample to abrade and mount it in holder directly under the outlet tube, so that the center of the flow will hit the center of the sample.
3. Position the sample so that the nearest portion of it to the end of the outlet tube is exactly one (1) inch from the outlet tube.
4. Fill the one liter beaker with sand to exactly the 1000 mL mark.
5. Load the upper funnel with the sand, thus allowing sand to abrade the sample.
6. Record each 1L of sand used.
7. Repeat steps 4 through 6 until the sample begins to show substrate, but empty the collection bin of its sand before the sand "backs up" onto the sample.
8. Once substrate begins to show, switch to using 250 mL at a time by using the plastic beaker.
9. Make sure to record exactly the total volume of sand used.
10. The run is complete once a patch of substrate is exposed that measures 4mm in diameter (no more, no less). Use the longest diameter if the patch is not circular.
11. The final piece of data for each sample is then the volume of sand required to expose a 4mm diameter patch of substrate.