Valco electronic Valve Oven - Manual (Page 7)

Operating Manual vii
Instrument Markings and Symbols
The following table explains the symbols used on Thermo Finnigan instruments.
Not all of them are used on the TRACE GC Ultra gas chromatograph and Valve
Oven.
Symbol Description
Direct Current
Alternating Current
Both direct and alternating current
Three-phase alternating current
Earth (ground) terminal
Protective conductor terminal
Frame or chassis terminal
Equipotentiality
On (Supply)
Off (Supply)
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