The Rossum Sand Tester can be used to measure sand content in any water system. However, the water sample for sand determination must be carefully obtained. A sample collected from a horizontal pipe at low flow is unacceptable. The sample should be obtained from a vertical or horizontal pipe with highly turbulent flow. Samples taken immediately downstream from elbows, tees, and other fittings that create turbulence are generally satisfactory.
1. Click here to see a video of how to assemble the device. Install the Rossum Sand Tester according to instructions provided. The inlet should be located on the horizontal centerline of the discharge pipe and be as close to the discharge head or other turbulent flow area as possible.
2. Completely open the inlet valve to the tester. Adjust the outlet valve to 1/2 gpm (this will fill a quart container in 30 seconds or a gallon container in 2 minutes).
3. Close the inlet valve, remove, clean, and replace the Pyrex tube.
4. When ready to start the test, completely open the inlet valve and note the time.
5. Periodically record the accumulated sand and time. It is important to note that the most common mistake made when doing the final calculation is dividing total accumulation of sand by total time. This provides only the average sand content. Instead, it is necessary to divide the incremental sand increase by the incremental time increase. This will provide the sand production at a specific time ie. sand production 15 minutes after the start of the test.
6. Check the flow rate through the tester during each run. If the flow rate is not 1/2 gpm, repeat the test.
7. Record the pump discharge rate (gpm) during each sand test and note whether any surging was done prior to the test.
RST Calculations -The sand content is determined from the following formula: Simplified:
incremental accumulation (ml) / incremental time (mins) Sand incremental sand accumulation (ml) x 528.3
ml sand per ml water = content=
.5 gpm x 231 in3/gal x 16.387 ml/in3 (ppm) incremental time interval (mins)
Therefore: Sand content (ppm) = ml sand per ml water x 1,000,000
Sample Worksheet Simple Calculation