The FRITSCH Variable Speed Rotor Mill PULVERISETTE 14 classic line is designed for rapid, efficient comminution of soft to medium-hard, brittle, fibrous, and temperature-sensitive materials, widely used in trace analysis. It operates by impacting samples on high-speed rotor ribs and shearing them between rotor teeth and sieve rings. Extremely sensitive materials like styrenes, polyester, and plastics can be embrittled with liquid nitrogen before grinding. The motor speed is adjustable from 6,000 to 20,000 rpm in 1,000 rpm steps, allowing precise adaptation to each sample. An automatic speed compensation feature optimizes grinding performance while minimizing thermal stress on samples, ensuring consistent, high-quality results across diverse applications.