4
Operation
Entering Parameters
Thermo Scientific
Fresco 17 / 21
4-5
Pre-selecting Speed
1. Enter the desired value by pressing the key
repeatedly, until the desired value shows.
You can adjust the speed in 100 rpm increments.
2. Press the
key to confirm the pre-selected value.
If you do not press any key, the display flashes for a few seconds
.T
he new preselected value is now
stored and the display shows the actual value.
Pre-selecting RCF-Value
1. Enter the desired value by pressing the key
repeatedly, until the desired value shows.
You can adjust the RCF pre-selected value in steps of 100 x
g.
2. Press the
key to confirm the pre-selected value.
If you do not press any key, the display flashes for a few seconds
.
The new preselected value is now
stored and the display shows the actual value.
Note
The centrifuge speed can be set to a minimum of 300
rpm.
The maximum speed depends on the centrifuge variant.
Note
The RCF value can be set to a minimum of 100 x
g.
The maximum speed depends on the centrifuge variant.
The displayed RCF value is always corresponding to the maximum of centrifuge radius of the
24 x 1.5 / 2.0 mL Rotor
(75003424).
Refer to the
and the rotor manual for further
information.
Explanation of RCF-Value
The relative centrifugal force (RCF) is given as a multiple of the force of gravity g. It is a unitless
numerical value which is used to compare the separation or sedimentation capacity of various
centrifuges, since it is independent of the type of device. Only the centrifuging radius and the speed
come into play in it:
r = centrifuging radius in cm
n = rotational speed in rpm
The maximum RCF value is related to the maximum radius of the tube opening.
Remember that this value is reduced depending on the tubes and adapters used.
This can be accounted for in the calculation above if required.
n
1000
-------------
2
r
×
RCF
11
.
18
×
=
