8 Performing a Measurement
D52IB001EN-G
61
8.8 Temperature Control Information
This chapter provides general information related to
heating and cooling of the samples.
8.8.1 Sample Temperature Accuracy
All specified temperature values in this instruction
manual refer to the temperature of the sample hold-
er and not the sample.
Depending on the operating conditions, the tem-
perature of the sample surface probed with the X-
ray beam can deviate significantly from the tem-
perature of the sample holder displayed on
CCU 100.
Especially for measurements with vacuum inside
the TTK 600 sample chamber, the deviation can
reach several 10 °C.
The deviation between the temperature of the sam-
ple surface and the displayed temperature mainly
depends on the following properties:
• temperature range
• atmosphere inside TTK 600 (gas type, vacuum)
• sample (thermal properties, surface)
• condition of graphite foil
Anton Paar GmbH only ensures the accurate mea-
surement and correct display of the sample holder
temperature. All parts are checked before delivery.
In order to avoid experimental errors caused by the
inevitable difference between sample holder tem-
perature and sample surface temperature, Anton
Paar GmbH strongly recommends that you do tem-
perature validation measurements for your particu-
lar experimental conditions. Such validation
measurements are done with reference materials
with accurately known thermal properties, using ei-
ther a crystalline phase transformation or thermal
lattice expansion. Lists of reference materials with
thermal data and instructions for doing validation
measurements can be found in the XRD literature.
TIP:
Try to avoid measurements in vacuum, be-
cause temperature deviation in vacuum is much
larger than if the chamber is filled with gas. When-
ever possible, use dry nitrogen or helium gas in-
stead of vacuum.
8.8.2 Effective Heating and Cooling Rate
Independent of the maximum set-point rate (SPR)
value which you can define, the maximum heating/
cooling rate which you can actually achieve de-
pends on your experimental conditions.
Due to the response time of the system, the
CCU 100 needs some time to reach the pre-set
heating/cooling rate (SPR). In addition, the heating/
cooling rate must be reduced by the CCU 100 when
the temperature approaches the temperature set-
point to avoid temperature overshoot.
As a consequence:
• the total effective heating/cooling rate for the
complete temperature step is a little smaller
than SPR, depending on SPR and the amount
of temperature change.
• it does not make sense to define small tempera-
ture changes with very large heating rates,
because the effective heating rate is limited.
SPR should be chosen in such a way that the theo-
retical time for the temperature change is
≥
1 min.
8.8.2.1 Standard Sample Holder
Exemplary maximum heating and cooling rates for
the standard sample holder can be found in the
graphs below.
Fig. 61: Exemplary maximum heating and cooling rates
for the configuration with liquid nitrogen cooling
equipment (upper graph) and compressed-air cooling
unit (lower graph) as a function of the temperature
and the used atmosphere.
Summary of Contents for TTK 600
Page 2: ......
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 ...
