Biobase LC-4KC, User Manual, Page: 12 / 71

3
3. The operation principles
The centrifuge machine helps to separate, condense or purify the different density components (or
particles) of the solutions by the usage of centrifugal sedimentation principal.
After placing the centrifuge tubes with equivalent test solutions in the test tubes around the rotors
symmetrically and starting the machine, the RCF produced in the high-speed rotary of the rotors,
which are driven by the motor, separates the different density components (or particles) in the test
solutions. The value of RCF depends on the rotating radius “r” (the horizontal distance from the
position of the test solutions to the axle center) and the rotating speed “n”, and here is the calculation
formula.
RCF
＝
1.118×10 -6 n 2 r×g
n------------ The rotating speed (r/min)
r------------The rotating radius (mm)
The time (Ts) needed during the separation and deposition of the mixed solutions is calculated by
this formula:
Ts
＝
27.4×
（
logeRmax-logeRmin
）
μ
min
n 2 r 2
（
б-ρ
）
Type: R
max
------The rotating radius of the test solutions having the farthest distance with the
axle center
Rmin------The rotating radius of the test solutions having the nearest distance with the
axle center
ρ------The density of the mixed solutions (g/cm
3
)
μ------ The viscosity of the mixed solutions (p)
n ------ The rotating speed (r/min)
r------The particle’s radius (cm)
б------The particle’s density (g/cm 3 )