Keysight NFA Series Performance Verification And Calibration Manual page 4

WARNING
WARNING
This is a Safety Class 1 Product (provided with a protective
earthing ground incorporated in the power cord). The mains
plug shall only be inserted in a socket outlet provided with a
protected earth contact. Any interruption of the protective
conductor inside or outside of the product is likely to make the
product dangerous. Intentional interruption is prohibited.
If this product is not used as specified, the protection provided
by the equipment could be impaired. This product must be used
in a normal condition (in which all means for protection are
intact) only.
Safety Symbols
The following symbols on the instrument and in the manual indicate
precautions which must be taken to maintain safe operation of the
instrument.
iv
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
documentation.
This symbol indicates that the input power required is
Alternating current (AC).
This symbol indicates the position of the operating
switch for 'On' mode
This symbol indicates the position of the operating
switch for 'Stand-by' mode. Note, the instrument is
NOT isolated from the mains when the switch is in this
position.
To isolate the instrument, the mains coupler (mains
input cord) should be removed from the power supply.