r
-
...
Op
e
ra
t
ion
an
d
A
pplica
t
ion
s
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DC·V
o
lt
a
ge
M
easurements:
C
AU
TION
:
S
e
e Maxi
m
um
Input
Vo
l
tages
,
unde
r
ELECTRICAL
SPECIFICATIO
N
S
,
When mak
i
ng d
c
-
vo
l
t
ag
e
mea
s
u
remen
t
s,
t
he slid
i
ng
sw
i
tch on the
W
G-299B
p
r
o
be should b
e
set to "DC"
.
Th
e
WV
-77
C
has fi
v
e d
c
-
v
o
l
tage
ra
n
ges
:
0 to 3
,
12
,
60, 300, and 1
2
00 vo
l
ts.
Al
t
houg
h
the met
er
is pro
-
tected
a
ga
inst
b
u
rn
-
out
,
it
is goo
d
p
ra
ctice
to m
ak
e
a t
r
ial
measureme
n
t
at a
hi
g
h
er
ra
n
g
e
se
tt
ing
t
h
an
is
consid
e
red
necessary
,
because
lo
n
g
-
co
n
ti
nu
ed
or
re
-
pea
te
d
overload
of the
me
ter
move
m
en
t
may
e
v
en
tu-
a
lly i
m
pair
the
ac
c
uracy o
f i
ndi
cat
ion.
To
m
eas
u
re
d
e
v
olt
ages
,
proceed
as
o
u
tlin
e
d
below
:
1.
S
e
t
th
e f
u
nction
s
el
ector
to
"+
VO
L
TS
"
or to
"
-
VOLTS",
as
r
equ
i
red
.
2
.
Connect t
h
e Grou
n
d
Cable cl
i
p
t
o g
r
o
u
nd
or
low
side
o
f source voltage.
CAUTION:
See first pa
r
agraph
o
f
"
Sa
f
ety Preca
u
·
t
i
o
n
s"
on page
2
.
3
.
Set t
h
e range
s
el
ector
to a posit
i
o
n
c
o
n
si
d
er
a
bly
h
i
gh
er
th
an
t
h
e voltage
to be measured.
4_ To
u
c
h
o
r
connect t
h
e DC
/
Direct
Probe
t
o
t
h
e
h
i
gh
side of
th
e
s
ource voltage
.
5
.
Reset
the rang
e
selector
to a position
which
gives
a su
it
able
pointer
deflect
i
o
n
.
6.
Read
th
e dc v
o
ltage
fr
o
m
the s
c
a
l
e corres
p
onding
to th
e r
a
nge
-
s
el
ector
setti
n
g
.
Zero~Center Indication:
Z
e
r
o
-
c
enter
indication
is frequen
t
ly
u
s
ef
ul
because
i
t
allows
observat
i
on
of either
p
o
s
i
t
ive
o
r
n
e
ga
t
ive
dc
-
voltage
exc
ur
sions
w
i
thout
the
ne
c
e
s
sit
y
o
f r
ese
ttin
g
t
he
f
u
n
cti
o
n
se
l
ect
o
r
.
1. Set the
f
u
nction
se
l
ec
tor
to
"+
VOLTS
"
.
2.
Rotate
t
h
e ZERO
AD]
Q9
n
t
r
o
l
to positi
o
n
the
pointer
at the cente
r
H
_O+
"
.
3
.
S
e
t
t
h
e r
a
n
ge
selector
to a posi
tion
at l
e
ast d
ou
ble
the volt
a
ge
to be
m
ea
sure
d.
4.
Aft
er
a tes
t
reading
has
b
e
e
n
made,
t
h
e
r
a
n
ge
selector
m
ay
be set t
o
th
e
l
owe
s
t
positi
on
w
hich
allows the po
i
n
t
er
t
o r
e
mai
n
on the scale
.
Resistance Measurements
:
W
h
e
n
mak
in
g
res
i
sta
n
c
e
me
asurements,
the
s
lidin
g
sw
i
tc
h
on t
h
e WG·2
9
9B
p
robe sho
ul
~ be
s
e
t t
o "OHMS
"
.
B
e
for
e
res
i
st
an
ce
measu
r
ements
are made
,
t
h
e p
o
wer
should
b
e
r
emoved
f
r
o
m
th
e
eq
uipment
under
t
es
t
so
t
h
a
t no
v
o
lt
a
ges
are
p
r
e
s
e
nt
in
th
e equ
i
p
m
e
n
t.
1.
Set the function
selector
to "OHMS"
posit
i
o
n
.
2_ Set th
e
range
se
l
ector
to
t
he pos
i
tion
n
earest
to t
h
e
value under
measurement
.
3
.
Connect
t
he prob
e
tip to the ground
clip and ad
j
ust
t
h
e ZERO ADJ control to p
o
s
it
ion
the pointer
at
t
h
e
l
ef
t
-
h
and
"0
"
,
if n
e
c
es
sary
.
4
.
Dis
c
onn
ec
t
the
WG-2
9
9B
p
r
obe
from
t
he Ground
Cli
p
.
Me
t
e
r
po
i
nt
e
r
w
i
l
l
deflect app
r
oxim
a
t
e
l
y
f
u
ll
sc
ale.
If
me
t
e
r
pointer
do
es
not deAect to exactly
full
s
cal
e,
u
s
e
OHM
S
A
DJ
c
on
t
rol
to adju
s
t
setting
a
c
cu
r
at
e
l
y
to the
l
ast
l
i
ne
on t
h
e
"
R
"
s
c
ale.
See
Ohms
A
d
j
ustmen
t
section
on
p
age
1
2
i
f
it i
s neces
-
sar
y
to freque
n
tl
y
readjust
the
OHMS
ADJ co
n
t
r
o
L
5
.
Conn
e
ct
th
e cl
i
p of the Gro
un
d
Cable
to o
n
e ter-
mina
l
of th
e
res
i
stance
to be
m
eas
ur
ed
.
6
.
Touc
h
or conne
c
t
t
he probe
t
ip
to the ot
he
r
te
r
-
e
minal
of the,
'
r
es
I
s
t
an
c
e
to b
e
meas
ur
ed.
7.
Res
e
t
t
he
ra
nge
s
w
i
tch to g
i
ve a conve
nien
t
de
fl
ec
-
t
i
o
n
on th
e
"R"
(ohms)
sca
l
e
.
8.
Mu
lt
i
pl
y
t
h
e reading
on the
"
R"
sca
l
e
by
the f
ac~
t
or
in
dicated
at
th
e range
-
s
el
ec
to
r
sett
ing.
CAUTIO
N
:
Low
-
c
u
rre
n
t
,
l
ow
-
resista
n
ce
dev
i
ces,
s
u
c
h a
s thermoco
u
ples
and meter
moveme
nt
s,
ma
y
be d
a
maged
u
nl
e
ss
a range
ab
o
ve
"
R xl"
i
s us
e
d
because
t
he \
V
V
-
7
7
C appli
e
s
up to
1.
5 vo
l
ts across
the res
i
sta
n
c
e
u
nder
m
e
asure
m
en
t
w
h
en the
rang
e
selector
i
s se
t
at "R
x
l
"
.
In the
c
a
s
e
o
f re
s
i
s
t
a
n
ce
m
ea
su
r
ement
s,
the WG
-
2
99B
p
robe
o
f
the
WV
-
77C
i
s
a
l
ways
po
si
t
i
ve
w
i
th
r
espect
t
o
th
e G
r
o
u
nd
Cab
l
e
. T
his faci
li
tates
the meas-
ure
m
ent
of
l
e
akage
re
s
i
s
tance
in
co
mponents-
suc
h
as
elect
r
o
l
yt
i
c
capacito
r
s
w
her
e
po
l
arit
y
must b
e
obs
erv
ed.
Measurement
of Resistance Values Above 1000
Megohms:
The
leakage
resistance
of
small
mi
ca
and
pa
per
ca
p
aci
t
ors
is usuall
y
above
1
000
megoh
ms
.
T
h
e
ci
r
~
c
u
i
t
s
h
ow
n
in
F
ig
.
2 can be
u
sed to meas
u
re
res
istan
c
e
values
above
1000
megoh
m
s.
An exte
rn
al
d
e vo
lta
ge
A
•
RX
RESISTANC
E
B
E
ING
MEASURED
WG-2998
SET
TO"OC"
EX
T
ERNAL
VO
LT
AGE
S
U
PP
LY
+
I
B
LACK
LEAO
F
igure
2
.
C
i
rc
ui
t
f
o
r
m
e
asu
re
m
e
nt
o
f
r
e
s
i
st
ance
v
alues
abo
v
e
1000
me
g
ohms .
•
6
•
Содержание VoltOhmyst WV-77C
Страница 13: ...I ...
