Specifications for Refrigerated Centrifuges

In a laboratory setting, a centrifuge is a device that spins a sample of liquid at a very high speed to separate substances of higher and lesser density. Centrifuges are cooled to prevent heat produced by the spinning from affecting the samples. There are three general sizes of centrifuges: micro, bench-top, and stand-alone. As of 2010, three of the primary manufacturers of refrigerated centrifuges included Hettich, Eppendorf, and MidSci.

Eppendorf

• In 2010, Eppendorf produced three varieties of refrigerated bench-top centrifuges: the 5702R, the 5804R, and the 5810R. Their spin speed ranges from 4,400 RPM to 14,000 RPM, and their maximum force ranges from 3,000 x g to 20,800 x g. The "x g" simply stands for the gravitational constant, or "g force," caused by Earth's gravity --- roughly 9.8 meters per second squared.

  The voltage of these centrifuges is either 120 V/50-60Hz or 230 V/50 Hz. In size, the 5702R is 15 by 22.8 by 10.2 inches, the 5804R is 25 by 22 by 13 inches, and the 5810R is 24 by 22 by 13 inches. Eppendorf also manufactures refrigerated microcentrifuges. In fact, it produced the smallest refrigerated microcentrifuge available in 2010: the 5415R, which achieves 13,200 RPM and 16,110 x g. The company's largest refrigerated microcentrifuge reaches a maximum of 17,500 RPM and 30,130 x g.

MidSci

• In 2010, MidSci was producing a refrigerated microcentrifuge called the Prism R, which achieves a maximum speed of 16,500 RPM and a maximum force of 17,135 x g. It was also offering a refrigerated version of its Z 233, the Z216-MK, which reaches 15,000 RPM and 21,000 x g. The 2010 Hermle bench-top centrifuges made by Midsci come in various levels: the Z36, the Z300K, the Z323K, the Z326K, the Z383K, and the Z400K. Their maximum speed ranges from 13,500 to 30,000 RPM, and their maximum force ranges from 17,310 x g to 65,390 x g. Their voltage is either 120 or 230V at 50-60 Hz.

Hettich

• As of 2010, Hettich offers micro, bench-top, and floor-standing refrigerated centrifuges. The Mikro 200R achieves a maximum speed of 14,000 RPM and a maximum force of 18,626 x g. It weighs approximately 62 pounds and uses 240 volts. The 220R achieves 18,000 RPM and 31,514 x g. It weighs 92.5 pounds and also uses 240 volts. The bench-top varieties, including the Universal 320R, the Rotina 380, the Rotina 420, and the Rotina 460, reach a maximum speed of 15,000 RPM and a maximum force of 21,382 x g to 24,400 x g. They weigh between 114.5 and 324 pounds, and they use 240 volts. Hettich produces two floor-standing varieties: the Rotixa 50RS and the Roto Silenta 630 RS. The Rotixa has a maximum speed of 4,900 RPM and a maximum force of 5,530 x g, and the Roto Silenta achieves 4,500 RPM with a maximum force of 6,498 x g. The Rotixa weighs 379 pounds, measuring 40.5 by 25.5 by 28.25 inches, and the Roto Silenta weighs 793.5 pounds, measuring 38.25 by 32 by 40 inches.