2 TTK 600 - An Overview
D52IB001EN-G
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2.5.3 Control of the Sample Cooling
Depending on the instrument configuration,
CCU 100 controls either the liquid nitrogen cooling
(LN2) or the compressed-air cooling equipment.
In order to be able to cool the sample, the com-
pressed-air source has to be connected to the con-
nector AIR IN on the rear panel of CCU 100. If the
controlling of the LN2 cooling equipment is active,
CCU 100 switches a valve inside which is connect-
ed to the AIR OUT connector. By switching this
valve the compressed air is directed to the Venturi
nozzle on the safety box or not. The Venturi nozzle
is creating a vacuum in the hose to the Dewar ves-
sel if the compressed air is on. Due to that liquid ni-
trogen is transported from the Dewar vessel to the
cryostat of TTK 600. If no cooling is required, the
compressed air is switched off.
Cooling automatically starts if the set point tempera-
ture is below the Cooling Limit (CL) of the instru-
ment. This value can be changed between 20 and
50 °C. For further details on how to change this pa-
rameter see chapter 6.3.1.
If the compressed air cooling equipment is used, the
compressed air supply is also connected to the AIR
IN connector on CCU 100. If cooling is required, a
valve inside CCU 100 connects the AIR IN to the
AIR OUT connector, which is connected to the air
cooling unit on the sample chamber.
In case that no cooling is required, the valve be-
tween AIR IN and AIR OUT closes.
2.5.4 Overheat Protection
TTK 600 has two devices to prevent overheating of
the instrument. The water flow controller (cat.no.
164877) monitors the flow of cooling water through
the housing of the sample chamber. It is a water flow
dependent switch, which is connected to CCU 100.
If there is not enough water flow, CCU 100 switches
to Standby (heater off) mode, the Error LED on the
front panel starts to flash and shows an alarm mes-
sage (E03).
In addition, a thermoswitch is mounted on the sam-
ple chamber to protect the device from being over-
heated in case of a malfunction. The thermoswitch
interrupts the heating power circuit if the tempera-
ture of the chamber housing exceeds 70 °C.
CCU 100 automatically switches to Standby mode
(heater off) and shows an alarm (E04).
TIP:
A list of all error messages can be found in
2.6 Water Flow Controller
The Water Flow Controller (cat.no. 164877) con-
sists of two components to control and monitor the
cooling water flow through the TTK 600 sample
chamber housing. The pressure regulator is used to
reduce the pressure from the cooling water supply
and set it to the required value of 2 bar. The water
flow monitor is a flow dependent switch which de-
tects if the water flow is below the required minimum
value. The flow monitor is connected to CCU 100
and switches off the heating power in case of insuf-
ficient water flow.
Fig. 22: Pressure regulator
Fig. 23: Water flow monitor
WARNING
Risk of injury.
When the cooling water supply to the chamber
fails, the housing can have a hot surface. In case
of an E03 error, turn off the heater by pressing
the HEATER button and do not touch TTK 600.
Carefully check the temperature of the TTK 600
housing and make sure the housing is at room
temperature before you touch it. Make sure that
you have found and removed the cause of the
error before you continue operation of TTK 600
and CCU 100.
Summary of Contents for TTK 600
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Page 74: ...Appendix B Sample Chamber Dimensions 74 D52IB001EN G Appendix B Sample Chamber Dimensions ...
Page 75: ...Appendix C Declaration of Conformity D52IB001EN G 75 Appendix C Declaration of Conformity ...
Page 77: ...Appendix D Spare Parts and Accessories D52IB001EN G 77 176383 COOLING MODE SWITCHING VALVE ...