HP 3478A Technical Manual Download

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TM 11-6625-3071-14

3478A

calibrated decade resistor with settings that range from
30ohm to 30Mohm or 10ohm to 10Mohm. The
correction factors on the decade resistor’s calibration
chart must be algebraically added to the 3478A reading,
to achieve the required accuracy. The Standard
Resistors and critical requirements are as follows:

a. 10 ohm, 100 ohm, and 1K ohm Standard

Resistors. Use the Guildline Model 9330A/10 or
9330A/10 for the 30 ohm Range, Model 9330/100 or
9330A/100 for the 300 ohm Range, and Model 9330/1K
or 9330A/IK for the 3K ohm Range. The accuracy
requirement is + .0005°o or better.

b. 10K ohm and 100K ohm Standard Resistors.

Use the Guildline Model 9330/10K or 9330A/O1K for the
30K ohm Range and Model 9330/100K or 9330A/100K
for the 300K ohm Range. The accuracy requirement is +
.001o or better.

c. 1M ohm Standard Resistor. Use the Guildline

Model 9330/IM for the 3M ohm Range with i.002%o or
better accuracy.

d. 10M ohm Standard Resistor. Use the Guildline

Model 9330/10OM for the 30M ohm Range with + .01%
or better accuracy.

4-15. DC Current Test And Calibration

4-16. The DC Current Test and Calibration requires an
AC-DC Current Calibrator as the current source, a Digital
Voltmeter for the standard, and a DC Volts Standard for
a stable voltage source. The following lists the required
equipment and recommended models.

4-17. AC-DC Current Source. The Valhalla Model
2500 is the recommended AC-DC Current Source. The
critical requirements are as follows:

a. Required current is 100mA and IA.
b. Required accuracy is + .03%.

4-18. Digital Voltmeter. The recommended Digital
Voltmeter is an -hp- Model 3456A. Refer to paragraph 4-
8 for the critical requirements.

4-19. DC Volts Standard. The DC Volts Standard is a
Systron Donner Model M107 Precision Voltage Source.
Refer to paragraph 4-9 for the critical requirements.

4-20. AC Current Test and Calibration

4-21. The AC Current Test and Calibration requires an
AC-DC Current Calibrator as the current source and an
AC Calibrator as the ac standard. The following lists the
required equipment and recommended models.

4-22. AC-DC Current Source. The Valhalla Model
2500 is the recommended AC-DC Current Source. The
critical requirements are as follows:

a. Required current is 100mA and IA.
b. Required frequency response is: 1KHz and 5KHz.
c. Required accuracy is +.03%.

4-23. AC Calibrator. The recommended AC Calibrator
is a Fluke Model 5200A. Refer to paragraph 4-11 for the
critical requirements.

4-24. TEST CARDS

4-25. Performance Test Cards are provided at the end
of this section and are to be used to record the 3478A's
performance. It is recommended to fill out the cards and
refer to them while doing the test. The test limits and
set-up information are printed on the cards for easy
reference. Since the 3478A's set-up information and test
limits are printed on the cards, the cards can be used as
an abbreviated test procedure (if you are familiar with the
test procedures). The cards can also be used as a
permanent record and may be reproduced without
written permission from Hewlett-Packard.

4-26. CALIBRATION CYCLE

4-27. A periodic performance verification is required for
the 3478A. This should be done as part of an incoming
inspection test and at a 90 day or I year interval,
dependent on your environmental condition and
accuracy requirements.

4-28. TEST FAILURE

4-29. If the 3478A fails any Performance Test, do the
necessary calibration dependent on what test failed (e.g.
do the DC Volts Calibration for a DC Volts Test failure).
If only one range fails, calibrate that range only (this is
only true for the DC Volts and Ohms Functions),
otherwise, calibrate the complete function. If the failure
can not be corrected by calibration, go to Section VII of
this manual for servicing information.

4-30. INSTRUMENT SET-UP

4-31. Instrument set-up is specified in each test and
calibration procedure. Except for the AC and DC Current
Performance and Calibration test signals, the signals can
be applied to either the 3478A's Front or Rear Input
Terminals. The signals for the AC and DC Current Test
and Calibration can only be applied to the front panel
terminals. Make sure the FRONT/REAR Switch is in the
correct position before applying the signals.

4-32. INSTRUMENT SPECIFICATION

4-33. Specifications are the performance characteristics
of the instrument which are certified. These specifica

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