Glossary
A tip filament TF practically is the upper filament of a dual filament. Only the topmost part of the crucible is being heated. This design provides the maximum temperature gradient between crucible bottom and lip.
Alternative filament types are Standard Filament SF, Cold Lip Filament CL, Hot Lip Filament HL and Dual Filament DF:

Alternative filament types are Standard Filament SF, Cold Lip Filament CL, Hot Lip Filament HL and Dual Filament DF:
