EXTECH
INSTRUMENTS
EX850-en-GB_v2.4 7/16
5
Operation
NOTES
:
Read
and
understand
all
Warning
and
Caution
statements
in
this
operation
manual
prior
to
using
this
meter.
Set
the
function
select
switch
to
the
OFF
position
when
the
meter
is
not
in
use.
AC
Current
Measurements
WARNING:
Ensure
that
the
test
leads
are
disconnected
from
the
meter
before
making
current
clamp
measurements.
1.
Set
the
Function
switch
to
the
AAC
or
ADC
range
2.
Press
the
trigger
to
open
the
jaw.
Fully
enclose
only
one
conductor.
For
optimum
results,
center
the
conductor
in
the
jaw.
3.
The
clamp
meter
LCD
will
display
the
reading.
DCA
ZERO
The
DC
Zero
feature
removes
offset
values
and
improves
accuracy
for
DC
current
measurements.
To
perform
a
zero,
select
ADC
and
with
no
conductor
in
the
jaw:
1.
Press
the
DC
ZERO
button
to
zero
the
display.
“
ZERO
”
will
appear
in
the
display.
The
offset
value
is
now
stored
and
remo
ved
from
all
measurements.
2.
To
view
the
stored
value,
press
the
DC
ZERO
button.
“
ZERO
”
will
flash
and
the
stored
value
will
be
displayed.
3.
To
exit
this
mode,
press
and
Hold
the
ZERO
button
until
“
ZERO
”
is
no
longer
in
the
display.
AC/DC
Voltage
Measurements
1.
Insert
the
black
test
lead
into
the
negative
COM
terminal
and
the
red
test
lead
into
the
positive
V
terminal.
2.
Set
the
function
switch
to
the
VAC
or
VDC
position.
3.
Use
the
MODE
button
to
select
AC
or
DC
Voltage.
4.
Connect
the
test
leads
in
parallel
to
the
circuit
under
test.
5.
Read
the
voltage
measurement
on
the
LCD
display.
Correct
Incorrect
