Extech
Instruments
6 GX900-EU-EN V1.6 4/14
SAFETY
INTERNATIONAL
SAFETY
SYMBOLS
This
symbol,
adjacent
to
another
symbol
or
terminal,
indicates
the
user
must
refer
to
the
manual
for
further
information.
This
symbol,
adjacent
to
a
terminal,
indicates
that,
under
normal
use,
hazardous
voltages
may
be
present
Double
insulation
This
symbol
advises
the
user
that
the
terminals
so
marked
must
not
be
connected
to
a
circuit
point
at
which
the
voltage
with
respect
to
earth
ground
exceeds
(for
this
specific
instrument)
1000VAC
or
VDC
WARNING
This
symbol
indicates
a
potentially
hazardous
situation,
which
if
not
avoided,
could
result
in
death
or
serious
injury.
CAUTION
This
symbol
indicates
a
potentially
hazardous
situation,
which
if
not
avoided,
could
result
in
damage
to
the
instrument
.
IEC1010
OVERVOLTAGE
INSTALLATION
CATEGORIES
OVERVOLTAGE
CATEGORY
I
Equipment
of
OVERVOLTAGE
CATEGORY
I
is
equipment
for
connection
to
circuits
in
which
measures
are
taken
to
limit
the
transient
over
‐
voltages
to
an
appropriate
low
level.
Examples
include
protected
electronic
circuits.
OVERVOLTAGE
CATEGORY
II
Equipment
of
OVERVOLTAGE
CATEGORY
II
is
energy
‐
consuming
equipment
to
be
supplied
from
the
fixed
installation.
Examples
include
household,
office,
and
laboratory
appliances.
OVERVOLTAGE
CATEGORY
III
Equipment
of
OVERVOLTAGE
CATEGORY
III
is
equipment
in
fixed
installations.
Note
–
Examples
include
switches
in
the
fixed
installation
and
some
equipment
for
industrial
use
with
permanent
connection
to
the
fixed
installation.
OVERVOLTAGE
CATEGORY
IV
Equipment
of
OVERVOLTAGE
CATEGORY
IV
is
for
use
at
the
origin
of
the
installation.
Examples
include
electricity
meters
and
primary
over
‐
current
protection
equipment.
