A common cause of crucible heater failure is improper installation. Great care must be taken when installing the heater to prevent the outer shields from becoming warped which can cause a short in the heater, causing the welded joints to fail. The heater should be centered between the contacts and the outer shielding clear of the leads.
Correct - Crucible heater centered, Incorrect - Crucible heater off-center,
outer shielding clear of leads shielding in contact with leads/inner shielding
Category: Evaporation Sources
Sub-Category: Crucibles and Crucible Heaters