By attaching a sieve to the top of the hopper, samples can be obtained which are representative of the initial sample while excluding all particles larger than the selected sieve size.

The Sieving Riffler has three basic components: A cylindrical vibrating hopper which is amplitude-variable and controls the delivery rate of the powder. A rotating sample collector which is divided into eight stainless steel compartments. And a replaceable sieve used to exclude particles above a selected size.

To accommodate a variety of materials the Sieving Riffler has two sets of controls. The powder delivery rate is controlled by the hopper's vibrational amplitude and by an adjustable gate at the hopper vent. The rotational rate of the collectors can be varied continuously or in three steps for exact reproducibility.

To divide a sample, the hopper (2500 cm³ capacity) is filled or partly filled with sample. The vibrator amplitude is set and the powder is automatically fed into eight stainless steel collectors. After all the material has been delivered into the collectors, further reduction in sample size may be achieved by emptying the contents of one or more of the collectors back into the hopper for additional reduction. By placing a sieve on top of the hopper, the Sieving Riffler will automatically exclude particles larger than the sieve size from the riffling process.