Model34904

Section V

S E C T I OVN

MAINTENANCE

5-r.TNTB0DUCTIoN.

5-2. This section contains performancetests and adjustment proceduresfor the Model 3490A Multimeter. The performance tests determine whether your instrument is operating within its published specifications.The adjustment proceduresareprovided to help you maintain your instrument within specificationlimits.

5.3.RECOMMENDEDTESTEOUIPMENT.

54.Test equipment required for the performance tests and adjustment proceduresis listed in Table 5-l . Any equipment that satisfiesthe critical specificationsgiven

in the table may be substituted for the recommended model.5.5TEST.RECOBD.

5-6. A PerformanceTest Recordis providedat the end of this sectionfor the purposeofrecording the results of the PerformanceTests.This record lists all of the tested specifications and their acceptable limits. This record can be removed from the manual and retained as a permanentrecord of the incominginspectionor routine maintenance performed on the instrument. This record may be reproduced for your usewithout specialpermis- sion.

PERFORMANCECHECKS
S7. PERFORMANCETESTS.

5-8. Use the following test procedures to determine whether your instrument is opefating within its published specifications. The test limits given in the accuracy tests and on the performance test record compare the instrument to the 90-day specifications given in Table l-l . However,if your accuracyrequirementsare met by other specifications, such as the 30-day or Gmonth specifications,the test limits should be adjusted accordingly. The performance of the instrument should be tested upon receipt and at regular intervals determined by your accuracyrequirements.Refer alsoto Mil. Spec.MIL{45662A.If the 3490A fails to meet one or more of its specifications, refer to the Adjustment Procedures,Paragraph5-51. The 3490A and test equipment should be operatedät normal line voltage with the 3490A rear panel line selector switchesset asinstructed in Figure 2-1. Allow at least one hour warm-up time for the 3490A before beginningthe following tests.

$9. DCVOLTMETERACCURACYTEST.5-10. A dc voltagestandard(-hp- 7a0B) is required for this test.Connect Guard to Input Low or damageto the instrument may result.a.Set 3490A FUNCTION to DC, RANGE to .l V.b.Connect dc standardbetween INPUT HIGH and LOW terminals.

c.Select3490A rangesand dc standardpositiveand negative outputs listed in Table 5-2. Display should be within limits shown in eachcase.

$ 11 .ACVOLTMETERACCURACYTESTS .

5-l 2. Becauseof the voltagerangeand bandwidth of the 3490A ac voltmeter circuits,more than one test setupis required to verify the accuracyspecifications.The -hpModel 745A/746A AC Calibratormay be usedto check the accuracyof all rangesat frequenciesup.to I l0 kHz; however,the accuracyof this sigral sourcealone in some casesmay not be greatenoughto ensurea valid test of

Table5-2. DC Voltmeter Accuracy.

3490A

DC Standard

 

Display Limits

Range

 

Output

 

 

 

 

 

r 0.010O0V

t

.009995to .010OO5V

. 1 V

r 0.05000V

l

.049990to .050010V

 

r 0.10000V

t

.099985to .100015 V

 

t o.10000v

I

0.09997to O.10003V

1 V

r 0.50000V

I

0.49994 to 0.50006 V

 

r 1.00000v

r 0.99990to 1.0001OV

1 0 v

1 1.00000V

!

00.9997to 01.Oq)3 V

 

i

10.0000v

t

09.9990to 10.0010V

100v

1 10.0000V

t 009.997to 010.003V

 

r 100.000V

t 099.990to 10O.O10V

 

I

100.000v

10099.97to 010O.O3V

1000v

i

500.000v

r

0499.92to 0500.08 V

 

r+

1000.00v

+

(x199.86

 

 

to 1000.14V

*lf -hp-7408 DC Standard is used, do not apply negative voltage greater than - 500 V.

5 - l