Portable sieve shaker designed to outperform comparably priced equipment. Both models deliver superior accuracy and repeatability for particle separations for No. 4 to No. 200 (4.75mm to 75µm) size ranges. 1/4hp units combine a back and forth lateral motion with an up and down tilting motion which causes test material to travel in an orbit on sieve surfaces. Accommodates 8in (203mm) sieves and also accepts ISO 200mm sieves.  Free-standing bench-top Shakers hold a stack of six full-height sieves with a pan or twelve half-height sieves and a pan.  Uses a 15-minute mechanical-electrical timers with adjustable knob-stops for improved repeatability and a “hold” feature for continuous running.