HP 3438A - DC;AC Ammeter and Ohmmeter Accuracy

Model 3438A Section IV
AC CALIBRATOR
h D 745A
MULTIMETER
hp 3438A
HIGH VOLTAGE AMPLIFIER
hp 746A
Figure 4-2. AC Voltage Accuracy Test.
c. Set the Multirneter function to - 1nA and range
4-14. AC Ammeter Accuracy Test.
to 200p A.
4-15. An AC
Callbrator and AC Current Source are
d. Check all the Multimeter ranges, using the values of
required for this test.
KA and differential voltmeter readings shown in I'able 4-
4,
display should indicate within the
a. Connect the equipment as shown in Figure 4-4
limits provided.
using the decade resistor box to select
the value of Kt\. Set
the Multimcter function to -mA. Using the values of KA
Table 4-4. DC Ammeter Accuracy.
and AC Calibrator outputs ahown in rable4-5, check the
200~ A, 2 mA and 20 mA Multirneter ranges at the
frequencies listed.
Range
200pA
2mA
20mA
200mA
2000 mA
b. To check the 200 mA and 2000 mA ranges, it will be
necessary to use an ac current source. Connect the ac
current source to the Multimeter as shown in Figure
4-5.
Current
Level
10pA
50pA
100 PA
.1 rnA
.5 rnA
1 mA
1 rnA
5 rnA
10 mA
10mA
50 mA
100 mA
100 mA
500 mA
800 mA
c. Check the Multimeter 200 mA and 2000 mA ranges
l'or- the tolerances listed in l able 4-6.
4-16. Ohmmeter Accuracy Test.
RA
100kC2
?0.01%
1 kC2
? 0.01%
1
kC2
+- 0.01 %
lOC2
+ 0.01%
1C2
+ 0.02%
4- 17. A precision resistive decade box is required for this
test. This resistive decade should be calibrated to within a
tolerance of
k .0057h.
Differential
VM Reading
1.0000V
5.0000V
10.000 V
.10000 V
.50000 V
1.0000
V
1.0000 V
5.0000 V
10.000
V
.10000 V
,5000 V
1.0000 V
,10000 V
.50000 V
.SO000 V
a. Set the Multimeter to the k1L function and the 2011
range.
Multirneter
Display Limits
9.8to10.2pA
49.7to50.4pA
99.5 to 100.5 pA
,098 to ,102 mA
.497 to .504 rnA
.995 to 1.005 mA
.98 to 1.02 mA
4.97 to 5.04 mA
9.95 to 10.05 mA
9.8 to 10.2 mA
49.7 to 50.4 mA
99.5 to 100.5 mA
97 to 103 rnA
495 to 505 rnA
793 to 807 mA
NOTE: Abbreviated Performance Tests are in bold type.
b. Connect the equipment as shown in Figure 4-6.
Table 4-5. AC Ammeter Accuracy Test (200 p A Thru 20 mA Ranges).
Range
200
PA
2 mA
20 mA
AC Calibrator
Output Level
2.02 V
20.02 V
20.02 V
AC Calibrator
Frequency
100
Hz
100 Hz
100 Hz
R~
Value
100
kC2 + .l%
100
kC2 + .l%
10
kC2 + 0.1 %
Current
Level
20
pA
.2 mA
2 mA
Multimeter
Display Limits
19.4 to 20.6
PA
,194 to ,206 mA
1.94 to 2.06 rnA