HP 3478A Technical Manual Download

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TM 11-6625-3071-14

3478A

4-99. AC Currant Calibration and Test (Optional)

4-100. Since the DC Current and AC Volts Calibration
has been performed and the AC Current Performance
Test passed, the AC Current Calibration and Test need
not to be done. If there is any doubt about the accuracy
of the AC Current Function, the function can be
calibrated and checked using the Optional AC Current
Calibration and Test Procedures in the following
paragraphs. Refer to Table 4-11 for the AC Current
Calibration Signals, Performance Test Signals, and
Performance Test Limits. Each step in the table is
shown in parenthesis in the procedure. All test signals
are applied

Table 4-11. AC Current Calibration and Test

4-101. Equipment Required. The following is the
required test equipment for the AC Current Calibration
and Test.

AC Calibrator (Fluke Model 5200A Option 05)
AC-DC Current Calibrator (Valhalla Model 2500)

4-102. Calibration and Test Procedure. Do the
following:

a. Reset the 3478A by pressing the blue Shift button

and then the SGL/TRIG (TEST/RESET) button.

b. Make sure the front panel CAL ENABLE Switch is

set to the calibration enable position (the slot of the
switch is in the vertical position).

c. (Step #1.) Set the 3478A to the AC Current

Function and the 3OOmA Range.

d. Set the multimeter to the Single Trigger Mode by

pressing the SGL/TRIG button.

e. Set the AC Calibrator for a IV at 1KHz output.

f. Set the AC-DC Current Calibrator to the 100mA

Range.

g. Connect the AC-DC Current Calibrator to the AC

Calibrator as shown in Figure 4-5.

h. Connect the 3478A to the AC-DC Calibrator as

shown in Figure 4-5.

i. Press the blue Shift button and then the LOCAL

(CAL) button.

j. Using the 3478A’s Uprange and/or Downrange

buttons, adjust the reading on the multimeter until it
agrees with the output value of the AC-DC Current
Calibrator (if the output value is known).

k. Press the SGL/TRIG button once.

l. This completes the AC Current Calibration. If a

Performance Test is desired, continue with the next step.
Otherwise remove the 3478A and the AC Calibrator from
the AC-DC Current Calibrator.

m. (Step #2.) If a Performance Test is desired, set the

AC Calibrator for a IV at 5KHz output.

n. Set the AC-DC Current Calibrator to the O1mA

Range. Check the reading on the 3478A.

o. (Step #3.) Set the AC-DC Current Calibrator to the

100mA Range. Check the reading.

p. (Step #4.) Set the 3478A to the 3A Range.

q. Set the AC-DC Current Calibrator to the IA Range.

Check the reading.

r. Remove the 3478A and the AC Calibrator from the

AC-DC Current Calibrator. This completes the AC
Current Calibration and Test.

4-103. Ohms Calibration and Test

4-104.  The 3478A’s Ohms Function can be calibrated in
either the 2-Wire or 4-Wire Ohms Function.  It cannot be
calibrated in both. Make sure the multimeter is
calibrated in the function in which it will be used. If the
3478A is to be calibrated in the 2-Wire Ohms Function,
connect the Standard Resistors to the 3478A’s HI and
LO INPUT Terminals.  If the 3478A is to be calibrated in
the 4-Wire Ohms Function, connect the Standard
Resistors as shown in Figure 4-7.

4-105. Refer to Table 4-12 for the Ohms Calibration
Signals, Performance Test Signals, and Performance
Test Limits. Each step in the table is shown in
parenthesis in the procedure. All test signals are applied
to the INPUT Terminals.

4-106. Equipment Required. The following is the
required test equipment for the Ohms Calibration and
Test.

10 ohm

.005%; (Guildline Model 9330/10 or

9330A/10)

100 ohm

.005%; (Guildline Model 9330/100 or

9330A/100

1K ohm

.005%; (Guildline Model 9330/IK or

9330A/IK)

10K ohm

.001%; (Guildline Model 9330/10K or