Datron 1061 - Page 67

56
Set
up
DC-DC
Turnover
13.
Select
lV
range,
AC
+
DC.
Apply
'lV
500H2
and
perform
GAIN
autocal.
14'
Apply
+1V
DC
and
note
the
displayed
reading'
15.
Apply
-1V
DC
and adjust
R62
(DC
turnover)
for the
same
reading
as in
operation
(14).
(t3
digits).
16.
Repeat
(131
to
(15)
until
all
readings
are
the
same
to
within
*20
digits.
Set up
Coarse
Frequency
Response
17.
Select
100V
range,
AC;
apply
100V.
500H2
and
perform
GAIN
autocal. Apply
100V,
50kHz
and
adjust
C82 for
a
display
reading
of
100.000V
f20
digits.
(lf
necessary change
C81
to
a
value
which
permits
this
adjustment).
18.
Apply
100V,
100kHz
and
note
the
reading
error'
Adjust
C79 to
give
5
times
the
error
in the
same
direction.
19.
Repeat
(17)
and
(18)
until
the
50kHz
and
100kHz
readings
are
separated by
less than
20 digits.
20. Select 1V
range, AC;
apply 1V, 500H2
and
perform
GAIN autocal.
Apply 1V,50kHz
and adjust C84
for
a
display
reading
of
1.00000V
*20
digits.
(lf
necessary
change C85
to a value which
permits
this adjustment).
Set
up Crest
Factor
21. Apply
'lVRMS,
+ve
5:1 Crest
Factor
signal.
Adjust
R61
(crest
factor)
for
a display reading of 1.00000V
430
digits.
22.
Apply 1VRMS,
-ve
5:1
Crest
Factor
signal.
Check
that display
reading
is
1.00000V t30
digits.
23.
Apply
1
V,
500H2, and
perf
orm GAIN
Autocal.
Repeat
(211,
l22l
and
(23)
unt¡l crest factor
readings
are within
limits.
Linearity
Checks
24. Select lV
range,
AC
+
Dc.
Apply 1V
DC
and
perform
GAIN
Autocal.
25.
Apply
1.9V
DC
and
adjust
R27 value
(Factory
Selected
Value
-
FSV)
for
a
display reading
of
1.90000V
16
digits
(reducing
R27 increases
readingl.
26.
Repeat
(24)
and
(25)
until
both
correct.
27
Select 1V
range
AC.
Apply in turn
1V,
t00mV,
10mV,
at
500H2
and
check
that display
readíng
is
correct
to
within
t10
digits
of the
input
voltage.
28. Apply open
circuit
input,
set CAL/RUN
switch
to
RUN;
press
'Test'
and
check for a display
of
'PASS'.
Output
Buffer
Check
29.
Select 1V range,
AC
+
DC, no
filter.
Apply
1V
DC
and
set
CAL switch to
RUN.
Use
the
'A-B' computation
mode to null
out the reading:
press
STORE,
B,
then
(A-B).
30. Select
filter.
and leave to settle for at
least 30 seconds.
Check
that
the displayed reading
is within
*50 digits
of
zero.
L{Þ
31.
Repeat
(28).
The AC set-up
procedure
is
now
complete.
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