Thermo Scientific Sorvall ST Plus Series, Instructions For Use Manual

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4-2
LCD Control Panel
4. 2. Set Basic Centrifugation Parameters
This section explains how to set up the centrifuge with speed / RCF values, acceleration and deceleration
profiles, temperature (refrigerated models only), and other operating parameters.
4. 2. 1. Set Speed / RCF-Value
The centrifuge lets you set speed in rpm or as an RCF value (see “RCF Value Explained” below). You may set
speed either from within an ongoing centrifugation run (centrifuge running) or for the next centrifugation run
(centrifuge at standstill).
RCF Value Explained
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
are used for calculation:
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, buckets and adapters used.
This can be accounted for in the calculation above if required.
Proceed as follows to set a speed or RCF value:
1. Press the Arrow keys below the xg / rpm LED indicators (left in Figure 4–2 ) to toggle between RCF (in xg,
which means multiples of the force of gravity) and speed (in rpm, which is short for revolutions per minute).
The LED indicator xg or rpm is lit to indicate the selected mode, and the value in the LCD display switches
to an RCF or rpm reading. The example in Figure 4–2 shows the rpm reading (bottom) and the equivalent
RCF reading (top).
Figure 4–2:
15000
7999
Choosing between RCF / rpm and setting the Centrifuge Speed
2. Press the + or - key below the Speed field of the LCD display to set the desired value.
NOTICE
If you select an extremely low RCF value, it will be automatically corrected if the resulting speed
is less than 300 rpm. 300 rpm is the lowest selectable speed.
3. Release the + or - key when the desired value appears.
Doing so selects the speed setting for future centrifugation runs (until the next time you choose to change
this setting).