14
Purging the Stage Method 1
Method 1 uses recycled nitrogen gas produced by the LNP96 from the Dewar.
1.
Make sure the stage lid is in place and the stage door is closed.
2.
Switch on the temperature programmer and set the limit to 40°C.
Press the START button and wait
until the temperature limit is reached.
Press HOLD to hold the temperature at 40°C.
3.
Switch on the LNP96, set it to manual mode (see your controller or software user guide), and set
the speed to the maximum of 100.
4.
Connect the purging tube with the gas insert from the LNP tube into one of the gas purging valves
in the side of the stage body. Connect the spare gas insert into the other gas purging valve in the
other side of the stage body. Check that the Gas Inserts are securely locked into place.
5.
Block the hole in the white (or black) plastic pump connector found on the opposite side to the
purging tube and seal the narrow window tube to block it.
This action will divert all of the
nitrogen gas to the purging tube and through the Stage Chamber.
6.
With the nitrogen gas flowing through the Stage Chamber, block the gas outlet port for a few
seconds to allow pressure to build up, then unblock the port to release the gas. Repeat this for a few
minutes to purge the stage.
7.
The purging procedure allows mixing of nitrogen gas with the residual air inside the Stage
Chamber.
By pressurising the chamber with nitrogen gas and releasing it, the air inside the
Chamber is being diluted with the nitrogen gas.
8.
Remove the two Gas Inserts and unblock the pump connector and window tube.
9.
Change the LNP96 to AUTOMATIC mode so that the T96 automatically controls pump speed
during your cooling experiment
Please refer to your health and safety officer for instructions on how to handle liquid nitrogen safely and
ensure that you have the correct Personal Protective Equipment, (PPE).
