Keysight U1251B and U1252B User’s and Service Guide 3
Safety Symbols
The following symbols on the instrument and in the documentation indicate
precautions that must be taken to maintain safe operation of the instrument.
Direct current (DC) Off (supply)
Alternating current (AC) On (supply)
Both direct and alternating current Caution, risk of electric shock
Three-phase alternating current
Caution, risk of danger (refer to this
manual for specific Warning or Caution
information)
Earth (ground) terminal Caution, hot surface
Protective conductor terminal Out position of a bi-stable push control
Frame or chassis terminal In position of a bi-stable push control
Equipotentiality
Category III 1000 V overvoltage
protection
Equipment protected throughout by
double insulation or reinforced
insulation
Category IV 600 V overvoltage
protection
CAT III
1000 V
CAT IV
600 V