Dc Dc; Dc External Reference Test - Fluke 8506A Instruction Manual

8
506
Figure 4-3,
Connections
for
High
Range
DC
Voltage Tests
annunciator
flashes approximately
eight
times per
second). All other
features
on
the
UUT
must
be
in
the
power-up
configuration.
4.
On
the Reference
Divider,
set
the
Standard
Cell
voltage controls
to the standard
cell
certified
value.
Set
both
the input
and output
controls
to 10
volts.
5.
On
the
DC
Voltage Standard,
set
the
output
controls
for 10
volts.
Next
adjust
this
output
for a
null
reading on
the null meter.
6.
On
the
UUT,
verify a
reading between +9.9990
and
+10.0010.
7.
On
the
Reference
Divider,
set
the
input and
output
controls
to
100
volts.
8.
On
the
DC
Voltage Standard,
set
the
output
controls for 100
volts.
Next,
adjust
this
output fora
null
reading
on
the null meter.
9.
On
the
UUT,
verify
a
reading
between
+99.9974
and
+100.0026.
10.
On
the
UUT,
manually
select
1000V
range.
11.
On
the
UUT,
verify
a reading between
+99.990 and
+100.010.
12.
On
the Reference
Divider,
set
the input
and
output
controls to
1000
volts.
1
3.
On
the
DC
Voltage Standard,
set
the
output
to
approximately
1000V. Next
adjust
this
output
for a
null
reading
on
the null meter,
14.
On
the
UUT,
verify a
reading
between
+999.974 and
+1000.026.
15.
Set the
DC
Voltage
Standard
to standby,
16.
Reverse
the leads
at
the
DC
Voltage Standard
and
at
the
Standard
Cell terminals. In sequence,
set
the
DC
Voltage Standard output
to 10 volts,
and
return
this
instrument
to
operate.
17.
On
the
UUT,
manually
select the
10V
range.
18.
Now
repeat steps 4
through
15,
verifying
negative readings
on
the
UUT.
4-45.
AUTORANGING
TEST
4-46.
Test the
UUT
autoranging
feature using the
following procedure:
1.
On
the
UUT,
select
V
DC
function
and
AUTO
range.
2.
Connect
the
DC
Voltage Standard output
directly
to the
UUT
input.
3.
Vary
the
DC
Voltage Standard
output,
checking that the
UUT
autoranges up and
down
at
the points
listed
in
Table 4-3.
These
points are
approximate and
are
determined without
application of software calibration
factors.
Table 4-3. Autoranging
RANGE
OPRANGE
POINT
DOWNRANGE
POINT
DC VOLTS
100
mV
200
mV NA
IV
2.0V .17V
10V 20V
1.7V
100V
128V 12V
1000V
NA
120V
AC VOLTS
100
mV
125.000
mV
NA
300
mV
400.000
mV
110
mV
IV 1.25000V
0.352V
3V
4.000V
1.1V
10V 12.50000V
3.52V
30V
40.0000V
11V
100V 125.000V
35.2V
500V
NA
110V
4-47.
DC EXTERNAL REFERENCE TEST
4-48. Test the
DC
four-wire true
ratio,
using the
following procedure:
1.
Connect
test
equipment and
the
UUT
as
illustrated in
Figure
4-4.
2.
On
the
UUT,
select
V
DC
function
and
AUTO
range.
4-8