A.)Open main valve and evacuate unit to 1-2mm (Torr). Close main valve. B.)Switch on bombarder and increase to 250mA. Hold at this setting while maintaining pressure between 2 and 3mm (Torr) with main valve. C.)When the unit is at 75C/170F, increase current to 350mA. D.)Maintain pressure between 2 and 3mm (Torr) with main valve. E.)At 120C/250F, increase current to 450mA, reduce pressure to 1.5 Torr. F.)When the electrodes are completely red and the glass has reached 230C/450F, open the main valve for a few seconds and then switch off the bombarder. G.)With the main valve open, allow the tube to cool to around 50C/125F with a vacuum gauge reading less than 5 microns.
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