HP 3455A - Page 70

Model
3455A
Section V
h.
Disconnect the DC
Transfer Standard.
Set the 3455A
FUNCTION to
4-WIRE K OHMS and
RANGE to 1
.
i.
Using short
pieces
of
number 20
AWG
insulated solid
copper wire,
connect the 1
kilohm Standard
Resistor to the
3455A
INPUT and OHMS
SIGNAL
terminals in
a
4-wire
ohms
measurement
configuration.
j.
Adjust the 1
kilohm pot for a
3455A reading of
1.000000 kilohm.
k.
Disconnect
the
1
kilohm
Standard Resistor and
connect the 100 K
standard
resistor using the same
4-
wire ohm
measurement
configuration.
l.
Set the 34S5A RANGE
to 100.
m.
Adjust the 1
megohm pot for a 3455A
reading of
100.0000 kilohm
(±
1
count).
n.
Set the 3455A
RANGE to
1 . Repeat Steps i
throu^
m to
obtain
optimum adjustment.
5-15. RMS CONVERTER
ADJUSTMENTS (A1S Assy.,
Standard Model 3455A Only).
NOTE
For 3455A
Option 001
instruments, refer to
the
Average
Converter Adjustments
(Para-
graph
5-16).
Equipment
Required:
AC/DC Digital
Voltmeter (-hp-
Model 3490A or
3455A)
DC
Standard
(Systron Donner
Model 106A)
AC
Calibrator
(-hp- Model
745
A)
a.
Set the 345SA
controls as follows:
FUNCTION
ACV
RANGE
10 V
AUTO CAL
ON
GUARD
ON
TRIGGER
INT
MATH
OFF
AC-AC/DC(Rear Panel)
AC
b.
Connect a
short across the 3455A
INPUT
terminals.
c.
Set the
Digital Voltmeter
(DVM)
to
measure dc
volts
(auto
range). Connect the
DVM low input
terminal to TP6
and the high
input terminal to TPS.
d.
Adjust
R65 (PREAMP
OFFSET ADJ) for a
DVM
reading
of 0 V
± 10 microvolt.
e.
Connect the
DVM Low to TP6 and
High to
TPS.
Adjust
R56
(ABS
AMP OFFSET ADJ)
for a
DVM reading
ofO
V
±
10
microvolts.
f.
Disconnect
the DVM. Connect a
clip lead
between
TP3
and TP6.
Adjust R16 (INT
AMP OFFSET)
for a
345SA display
reading of 0
V ± 1 count.
g.
Remove the clip
lead from TP3
and TP6.
Adjust R29
(LOGGER AMP
OFFSET) for a
3455A display
reading
between 0.0998
V and 0.1002
V with a 100
mV, 100 Hz
signal
applied to the input
terminals.
h.
Set the
rear panel AC
-
AC/DC
switch to AC/DC.
Set
the DC
Standard for an
output of 10 V dc.
Connect the DC
Standard
output
(Negative Polarity) to
the 34S5A
INPUT.
i.
Note the 34SSA reading.
j.
Reverse the polarity of the
DC Standard’s output and
note the 34SSA
reading.
k.
Adjust R51 (AC- DC
TURNOVER ADJ) so that the
readings in Steps i and
j
are equal
±
0.0005
V.
l.
Disconnect the
DC Standard from the 3455A
INPUT.
Set the rear panel
AC-AC/DC switch to AC.
m. Set the 3455A
RANGE
to I
V. Connect the
DVM
(AC function,
autorange) Low to TP6 and
Hi^
to
TPS.
Set the AC Calibrator for an
output of 1 V, 100 Hz. Con-
nect the AC
Calibrator output
to
the 3455A
INPUT.
n.
Adjust R74
(1
V,
100
Hz ADJ) for a DVM reading
of
1.00000 V
±
1
count. Disconnect the DVM.
0
. Adjust R17
(GAIN)
for a
3455A reading of
1
.00000
V
±
5
counts.
NOTE
If,
in the following
steps, there is insufficient
adjustment range
for
the 1 V, 10 V or 100 V
high-frequency (40
kHz) adjustment, the
adjustment range can be expanded by
remov-
ing the
appropriate jumper wire on the A15
board (see Table
5-2). Refer to the AIS
board component locator
(Section
VIII) for
jumper locations.
p.
Set the AC
Calibrator frequency to 40
kHz.
Adjust
R75
(1
V, 40 kHz ADJ) for
a
34S5A reading of
1.00010
V
(tolerance
=
+ 20 counts).
q.
Set the 3455A
RANGE
to
10
V.
Set the AC
Calibra-
tor
for an
output
of
10 V, 100
Hz, Adjust R73 (10
V,
100
Hz ADJ) for a 3455A
display reading of
10.0000 V
±
5
counts.
T.
Set
the
AC
Calibrator frequency to
40 kHz.
Adjust
R72 (10
V.
40 kHz
ADJ) for a 3455A
reading of
10.0010
V (tolerance
=
+
20
counts).
s.
Set the
345SA
RANGE to 100
V. Set the AC Cali-
brator for
an output of
100 V, 100
Hz. Adjust R94 (100
V,
100
Hz ADJ) for a
3455A reading of
100.000
V ±
5
counts.
5-3