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 and to abrade the sample.
6. Record each 1 L 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 show3, 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 exposd that measures 4 mm 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 4 mm diameter patch of substrate.