100 000
95 000
90 000
85 000
80 000
75 000
70 000
65 000
60 00050 00040 00030 00020 00010 0002001 000 000900 000
800 000
700 000
600 000
500 000
400 000
300 000200 000100 000
90 00060 000
50 000
40 000
30 00020 00010 0009 000
8 0007 000
6 000
5 000
4 000
3 0002 0001 000180
160
140
120100
90
80
70
605040302010Radial distance
(mm)Relative centrifugal
fieldRotor speed (r.p.m.)80 000
70 000Fig. 3.1Nomograph for the determination of the relative centrifugal field for a given rotor speed and radius.
The three columns represent the radial distance (in mm), the relative centrifugal field and the rotor speed
(in r.p.m.). For the conversion between relative centrifugal force and speed of the centrifuge spindle in revolutions
per minute at different radii, draw a straight-edge through known values in two columns. The desired figure
can then be read where the straight-edge intersects the third column. (Courtesy of Beckman-Coulter.)77 3.2 Basic principles of sedimentation