I.C.E Supertester 680 R Operator's Manual And Repair Manual page 10

As
it
may
be
seen Jrom the electrical diagram relating to
alternating
current
voltage
measure-
ments,
our
SUPERTESTER
Model
680
R, as well as
almost
all
the
most
populai
Anrerican
analysers, has adopted.a rectifier circuit
with
only
one
half
wave becausd
ihis
system,
in
add.ition
to
measuring
the normal alternating current,
makes
it
possible to
check the iymmetry
of
the
arerage value
betYveen
the
two
aliernations
of tho alternating current
being
eiarnined.
ln
fact
in practice.it
may happen
that
tw'o half waves
of
an alternating current may
become
asymnletrical, i.e. that the two half
waves have not the
same
outline
anrl
the
same dmplitude.
An exairple would be the
presence of
a
direct
component.
Slrould
-this
asymmetry
affect the
average value,
it
may be
revealed
by the
l.C.E. Tester
lJlod. 680
R by
reversing
the
Ieads
at the
measuring
p0ints.
The cliffdrence betvreen
the
two
measurements
makes
it
possible
to
calculate
the
average value,
the
percentage
of
asymmetry present and therefore
the
v1-v2
%
of
asYmmetrY -
---
i00
V1
where
V1
:
maior
dcviation
V2
=
minor
deviation.
CURRENT MEASUREMENT
WIT}I O.C. (mA)
WARNINE:
F0r current
measurements,
the
instrument must
always
be
connected
in
series
with the circuit (see figure page
17).
Never cornect the instrument
in parallel
with
the
circuit live like with the
measurements
of
voltage (Volts),
because
the
resistances
and
shunts would
get
damaged, especially those wiih
a
loyr ohm
value.
Make sure
that with
current
measurements
(mA D.c.) the
black lead (negative)
is
inserted
as
faI.as it.will g0 into thc
lower
ceniral
socket marked with the
black
wordin!
on
a
white
ground
"="
(D.C.) and the other red one (positive) in
one marked
,'50
uA
- 500;A -
5 mA
-
50
mA
-
500 mA
-
5
Amp" according
to
the
range required.
It
is
most
i.mportant
to.bear
in
mind
that,
when
there
is
doubt about the
amplitude
of
the
current
to
be
measured,
the highest range
(5
A.)
should always
be
used
s6
at to
avoid
damaging the resistances
and shunts
in the
circuit.
14
subsequenfly,
if
required,
after the
first
reading,
the red lead
of
the various ranges may
be
insertrjd
int'o'
the n6xt lowest range so as
t0
obtain
a
more accurate
reading.
ioi
tf,e
ranges
100 pA,
1
mA,
10
mA,
100
mA,
1 A.and.10 A
D-C., use
the
sockets.of
the
,ine.i
5o
"1,
sOO uA,
S, 50, 500
mA
and
5 A, pressing
the
sensitivity buttcn
wh.ictt.
doubles
ttre"ianees-in consiheratl6n,
To
make anyway
this point clearer, the.following table
to
be
taien
in-to
accgunt
for
a
more accurate
ieading
of the scale, referring
to the
range
and
theref0re
to the
selected sockets.
Sel
ected
range
Sockets to
be
used
Se
nsiiivity
key
AVx 2
N u
mbering
to
be
read
on the
scale
Multiply
the
read-
ing
by
Divide
the
read-
ing
by
50
pA-
100
pA=
500
pA:
1 mA=
50
mA=
10
mA=
50
mA=
100
mA=
500 mA=
1A:
5A=
10
A=
and
50
pA-
and 500
y,A=
and
5
mA:
and
50
mA:
and
500
mA=
and
5
A=
,-)
(:)
(=)
(=)
(:)
RELEASE
DEPRESS
RELEASE
DEPRESS
RT.LEASE
DEPRESS
RTLEASE
DEPRESS
RII-EASE
DEPRESS
RELEASE
I}TPRESS
from
0 to
50
from
0 to
10
from
0 to
50
from
0 to
10
from
0 to
50
from
0
to
10
from
0
to
50
from
0 to
10
from
0 to
50
from
0
to
10
frcm
0 to
50
frnm
0
to
10
x10
1l'
,10
t'
:10
,I
10
10
15