Use of an arc: retrieving a frozen sample from a Dewar and mounting it on a goniometer

Fill a 2 litre intermediate Dewar and a glass sample handling Dewar with liquid nitrogen
Put the removable arc on the goniometer and position the magnet on it so that the top hat and pin will point downwards when on the magnet
Check that you can gain access to the magnet with the vial holders by doing a ‘dry run’ with an empty vial in the holder
Transfer the cryocane, which is holding the desired crystal, from the storage Dewar or dry Dewar to the 2 litre Dewar
Put the vial holders into the small Dewar to cool down
Put on a pair of cryogloves
Lift the cryocane out of the 2 litre Dewar and take out the required vial with the other hand or with the vial tweezers
Place the vial in the vial holder (or the vial tweezers) and place both into the glass sample handling Dewar
If there is a lid on the vial, remove it using the lid opener
Move the glass sample handling Dewar as close to the goniometer as possible. Bring the vial holders up underneath the magnet till the top hat is in contact with the magnet
Carefully withdraw the vial to leave the crystal in the nitrogen stream
Move the crystal around the arc by pushing on the metal bar on the Slider
Unscrew the removable part of the arc and proceed with the final crystal alignment.
Note: if the sliding part of the arc is too loose, tightening the small screws in the underside of the blue curved piece can tighten it