Keysight Technologies E4412A Operating And Service Manual page 9

Safety Symbols
ESD
E4412A and E4413A Operating and Service Guide
The following symbol on the instrument and in the documentation
indicates precautions that must be taken to maintain safe operation of the
instrument.
Caution, risk of danger.
The Instruction Documentation Symbol. The product is marked with this symbol
when it is necessary for the user to refer to the instructions in the supplied docu-
mentation.
This symbol indicates that a device, or part of a device, may be susceptible to
electrostatic discharges (ESD) which can result in damage to the product.
Observe ESD precautions given on the product, or its user documentation, when
handling equipment bearing this mark.
Alternating current (AC).
Direct current (DC).
Both direct and alternating current.
Three-phase alternating current.
Earth (ground) TERMINAL.
VII