Sieving Method

Sieving is conducted by using all metal sieves for a given range of grain sizes.

Steps

1. Set out a piece of paper for each sieve plus the pan and label them with the sieve range and sample ID. These will be used to pour the contents of each sieve as the sample is separated.

2. Gather available sieves from 150 µm to 350 µm in at least 100 µm increments. Using larger increments will make it more difficult during the picking stage. It is best to have a uniform grain size distribution.

3. Check sieves for errant grains within the mesh and remove. Proceed with caution as applying pressure on the mesh when removing grains. Too much pressure can warp and damage the sieve, reducing it’s lifetime.

4. Wipe each sieve with ethanol or acetone. This helps remove fine particles that may contaminate samples.

5. Stack the sieves along with the bottom pan and pour in enough sample to make a few layers of grains. Filling sieves with too much material will slow down how quickly you can reliably sieve the sample.

6. Shake the sieves and once the sample appears to have been sieved remove the top sieve and dump out it’s contents onto the labeled paper. Continue to shake the sieve while occasionally tapping the sieves on the table, encouraging the finer material to fall through the sieve.

7. After working yourself through the first round, repeat the steps by re-stacking the sieves and pouring more sample in until the sample is complete.