A.) Open main stopcock and pump unit(s) down to 20 microns, roughly 2 minutes if you do not have a vacuum gauge. Open vacuum gauge stopcock and check vacuum.
B.) Completely close main stopcock, vacuum gauge stopcock, and oil manometer stopcock (if you have one).
C.) Backfill unit(s) with 3.5 Torr (mechanical gauge) 3.5 Torr (oil manometer) of dry nitrogen.
D.) With the main stopcock, vacuum gauge stopcock, and oil manometer stopcock completely closed, switch on bombarder at lowest setting and immediately increase to 200 mA. (Note: If arc can’t be struck, slightly reduce pressure in unit. We recommend switching bombarder off when adjusting pressure to prevent flashback).
E.) Maintain pressure in unit(s) between 3 and 4 Torr (3 and 4mm). Note: When opening and closing main stopcock to remove accumulated pressure, be sure to switch off bombarder before opening main stopcock to prevent flashback.
F.) Continue bombarding until glass temperature reaches 150C/310F. At this point reduce and maintain pressure in unit(s) to 1 1/2 – 2 Torr (1 1/2 – 2mm) and increase the bombarding current to 250 mA, making sure to stop bombarding when you open the main stopcock to prevent flashback.
G.) Continue bombarding until glass temperature has reached 230C/446F, and the electrode shells have been heated to a bright red/orange over their entire length.
H.) Switch off bombarder, open stopcock on oil manometer (if you have one) and open main stopcock. After about 10 seconds, open stopcock on vacuum gauge and pump unit down to 5 microns or less.
I.) When units have cooled to approximately 50C/122F, close main stopcock, vacuum gauge stopcock and oil manometer stopcock (if you have one). You may now fill unit(s) to proper pressure and seal off.