Performing VT experiments using 400MHz DRX spectrometers

The case of higher than ambient temperature .

* Use the proper spinner turbine for VT experiments. Actually, the gray fiber glass spinners
   are design for VT experiments.
* Make sure that VT nitrogen gas is hook up to the glass Dewar in the probe and the flow
   takes place. The glass Dewar is very fragile, please take extremely cautions while
   working with it.
* While in xwinnmr software type ‘EDTE ’ command and EDTE main window appears.
* Make sure that target sample temperature is set up to room temperature.
* Set maximum heater power to 15% . It is rather rare that higher value will be needed.
   Turn heater “ON”
* Make sure that your target temperature does not exceed the limit of the probe
   specifications. Exceeding the probe’s limit temperature will damage the probe. Magnet
   might also be damaged.
* Set the temperature 5 degree higher than present and click the "APPLY" " OK " button
* Wait until sample temperature will be close to target and increase it for another 5 degree.
* To get to the final required temperature, proceed in the steps of no more than 5-8 degree
   to avoid thermal and current shock in the hardware.
* While in the required temperature wait certain period of time before you start to perform
   NMR experiment to equalize the temperature across the sample. The 20 –30 minute
   period of time is usually needed. However, you may like to find out your own waiting
   time for temperature equalization.
* After experiment is finished, decrease the temperature in the 5-8 degree intervals until the
   room temperature is achieved. Never introduce the thermal shock to the system by
   changing the temperature with too large intervals.
* Turn off the heater by clicking heater button “ Off” in the EDTE menu.
* Exit the EDTE menu.
* To cool down probe’s electronic and shims to the ambient conditions an additional time
   between 30–120 minutes is needed. This depend on how long experiment took place and
   what was the final temperature. Mark your VT experiment in logbook so a next user will
   be aware about previous conditions. Consider those limitation while signing up so the
   sign up policy will be obeyed.
*To find out more details, please refer to the Bruker manual that is available in NMR
   laboratory.
 
The case of lower than ambient temperature .
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