Begin your site preparation by choosing an area of the compacted surface that appears most level. You may have to remove some loose debris; however, make no attempt to pack or smooth the surface. Next, you seat the template tray flush on the surface, especially around the center hole. If necessary, seal any spaces around the center hole of the tray with modeling clay. Then force nails through the holes in the tray to hold it firmly in place. Now you are ready to perform the surface calibration.

Surface calibration accounts for surface irregularities of the area to be tested. With the valve closed, turn the sand-filled apparatus over and place the large cone over the center hole of the template tray. Open the valve and allow the sand to pass through until the large cone is completely filled. Do NOT shake or vibrate the apparatus. Then close the valve, weigh the apparatus with the remaining sand, and enter this weight on line 8 of DD Form 1215 (fig. 13-6A). The difference between the initial weight (line 7) and the final weight (line 8) is the weight of the sand that passed through the cone valve into the lower cone and the center hole of the template. Enter that weight on line 9.

After performing the surface calibration, recover as much of the sand from the tray as possible without disturbing the template tray or the soil in the hole. Brush the remaining sand particles lightly from within the tray. Leave the template in place for the volume-of- hole determination to be discussed next.

VOLUME-OF-HOLE DETERMINATION. The volume-of-hole determination consists of digging out a soil sample through the center of the template and computing the volume of the resulting hole. 

The hole that is dug through the center hole of the template tray should be about 6 inches deep and approximately the same diameter as the hole in the tray. When digging, keep the inside of the hole as free from pockets and sharp protuberances as possible. Make sure that ALL material removed from the hole is placed in a container of known and recorded weight (line 23, fig. 13-6B). Keep the lid on the container as much as possible to prevent excessive moisture loss until it is weighed. When all removed material has been placed in that container, immediately weigh it and record the weight of the container and the material on line 15. Mark the container for later identification when the soil moisture content is determined.

DENSITY DETERMINATION. Now that you have determined the volume of the hole, the only remaining requirements are to determine the moisture content and the dry density of the sample that was removed from the hole. The moisture content should be determined using the oven-dried method that you studied in the EA3 TRAMAN. Lines 15 through 21 of DD Form 1215 (fig. 13-6B) are used to record the moisture-content data.

The wet density or unit weight (line 25) is computed by dividing the wet soil weight (line 24) by 453.6 to convert the grams to pounds and then by the volume of the hole (line 14, fig. 13-6A). The dry density or unit weight is then computed using the formula shown on line 26 of DD Form 1215.