Thermo Scientific 11174729, Инструкция по эксплуатации

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Chapter 4
OPERATING PRINCIPALES
Thermo Fisher Scientific MR23i 4-3
terms of motor rotation speed (rpm). A given rotation speed corre-
sponds to centrifugal acceleration which is directly proportional to
the centrifugation radius, in keeping with the following equation:
For example, a given separation may be described as obtainable
by centrifuging the sample in a given machine (which determines
the accessory, thus the centrifugation radius) for 10 minutes (dura-
tion) at 4000 x g (R.C.F.) (Fig. 4.1).
The centrifugation curve is as follows:
Theoretically, if the centrifuge instantly attains the set point speed
and brakes instantly, and if the requested speed attained is con-
stant, reproducibility of results is guaranteed from one centrifuga-
tion to the next.
It is thus obviously equivalent to centrifuge a sample at 4000 g
during 10 minutes as to centrifuge it at 2000 g for 20 minutes (or
8000 g for 5 minutes) (Fig. 4.2).
In other words, centrifugations yield the same results when the pro-
duct: DURATION X CENTRIFUGAL ACCELERATION remains
constant. This product corresponds to the area of the curve.
Number of „g“ = 1.118 x R x N
2
Acceleration Centrifugation
radius (mm) Speed in thou-
sands of rpm