PerkinElmer LS 55, User Manual

Page: 117 / 202

Accessories: Installation and Use . 117
Filling the accessory with liquid nitrogen
WARNING
During filling of the liquid nitrogen tank, protective gloves
must be worn and care must be taken not to touch the metal
surfaces of the accessory with unprotected hands.
NOTE: During filling, an empty sample tube should be located in the accessory to
avoid icing in the sample holder position.
1. Remove the sample cover and gently push an empty sample tube vertically
into the hole in the black cover plate.
Some resistance will be encountered when the tube comes into contact with
the two clips which secure the tube, turn the tube if necessary to overcome
this resistance.
2. Remove the funnel cover and carefully pour liquid nitrogen into the funnel.
This will require approximately 3 L of liquid nitrogen.
Pour slowly until the tank overflows. When the copper finger has almost
reached temperature, the liquid nitrogen will boil for several seconds, after
this the system settles down.
3. When the boiling has subsided, the tank should be slowly filled to overflowing.
4. Close the funnel cover, remove the sample tube and replace the sample
cover.
NOTE: To maintain constant temperature, approximately 1 L of liquid nitrogen will
be required for each hour of use (depending on room temperature). The
accessory should be topped up with liquid nitrogen every 10 to 15 minutes
to ensure temperature stability.