The W.S. Tyler Ro-Tap Sieve Shaker, Model B (often associated with RX-29 or RX-30 models), is a standard instrument for particle size analysis in various industries. It simulates the circular and tapping motion of hand sieving, providing a unique two-dimensional operation that stratifies particles and allows them to seek critical openings in test sieves. This ensures accurate and consistent particle analysis. The Model B is designed for use with 8-inch diameter testing sieves and features a digital timer for setting durations up to 99 minutes with 0.1-second accuracy. It is built for heavy-duty use and requires minimal maintenance.