Prevent Cooling Being Switched On During Run-Out; Heating (Only On Centrifuges With Heating/Cooling Option); Relative Centrifugal Force (Rcf) - Hettich ROTINA 420 R Bedienungsanleitung

33.4

Prevent cooling being switched on during run-out

If necessary it can be set so that at the end of the centrifugation run during run-out, once the specified speed has
been attained, cooling is not switched on.
This avoids whirling up the sediment in the sample.
The speed can be set between 0 RPM and the maximum speed of the rotor (Nmax) in increments of 10.
When the rotor is at a standstill, the speed is set as follows:

Keep the key held down for 8 seconds.
PROG
After 8 seconds,  Machine Menu  appears in the display.

Press the key as often as necessary until the ->Settings is displayed.
PROG

Press the key. The SOUND / BELL = off/on is displayed.
START

Press the key as often as is needed until the Cool dec speed = ... rpm.
PROG

Use the adjusting knob

Press the key to save the setting.
START
Briefly, Store Settings ... is displayed as confirmation, followed by -> Settings.

Press the key once to leave the "Settings" menu or press the
OPEN / STOP
"Machine Menu".
34

Heating (only on centrifuges with heating/cooling option)

During operation of the centrifuge the centrifuge chamber can be heated as required to the preselected temperature.
The heating is switched off when the rotor is stationary.
Risk of burning! The surface temperature of the heating element in the centrifugal chamber of the centrifuge
can reach 500°C / 932°F. Do not touch the heating element.
Plastic suspension can only be used in temperatures up to a maximum of 40°C / 104°F.
The heater can also be deactivated, if needed.
When the rotor is at a standstill, the heater can be activated or deactivated as follows:

Press the key until Heater = on/off is displayed.
T/°C

Switch off or on with the rotary knob .
off = heater deactivated,
on = heater activated.

Press the or
START
T/°C
The centrifuge data is displayed.
35

Relative centrifugal force (RCF)

The relative centrifugal force (RCF) is given as a multiple of the acceleration of gravity (g). It is a unit-free value and
serves to compare the separation and sedimentation performance.
These values are calculated using the formula below:
RCF
RCF = relative centrifugal force
RPM = rotational speed (revolutions per minute)
r = centrifugal radius in mm = distance from the centre of the turning axis to the bottom of the centrifuge.
The relative centrifugal force (RCF) stands in relation to the revolutions per minute and the centrifugal
radius.
to set the value you want.
key to save the setting.
2
 
RPM
 
  
r 1,118
 
1000
For more on the centrifugal radius see the chapter " Anhang/Appendix,
Rotoren und Zubehör/Rotors and accessories".
OPEN / STOP
RCF
 
RPM

r 1,118
EN
key twice to leave the

1000
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