HP 3478A Technical Manual page 47

3478A
4-89. Calibration and Test Procedure. After the has
been warmed up for at least one hour, do the following:
a. Reset the 3478A by pressing the blue Shift button
and then the SGL/TRIG (TEST/RESET) button.
Resetting the 3478A automatically places the
instrument into
Autorange, Internal Trigger, and 5 Digits
Display mode.
b. Using a small flat blade screwdriver, set the front
panel CAL ENABLE Switch to the calibration enable
position (the slot of the switch is in the vertical position,
as shown on the front panel).
c. Set the multimeter to the Single Trigger Mode by
pressing the SGL/TRIG button.
d. (Step #1.) Short the 3478A's HI and LO INPUT
Terminals. Set the instrument to the 30mV Range (take
out of Autorange).
e. Press the blue Shift button and then the LOCAL
(CAL) button.
f. Press the SGL/TRIG (Single Trigger) button only
once and then remove the short from the Input
Terminals.
g. Set the DC Volts Standard for zero volts output.
h. (Step #2.) Connect the 3478A to the Digital
Voltmeter and DC Volts Standard, as shown in Figure 4-
2. Use the Digital Voltmeter as the standard and the DC
Volts Standard as a stable power supply.
i. Set the DC Volts Standard's output for + 30mV and
note the reading on the Digital Voltmeter.
j. Press the blue Shift button and then the LOCAL
(CAL) button.
k. Using the 3478A's Uprange and/or Downrange
buttons, adjust the reading on the multimeter until it
agrees with the reading on the Digital Voltmeter.
l. Press the SGL/TRIG (Single Trigger) button once.
m. (Step #3 and 4.) Remove the Digital Voltmeter and
the DC Volts Standard from the 3478A.
3478A's HI and LO INPUT Terminals and set the
instrument to the 300mV Range.
n. Calibrate the 300mV Range (applying zero and full
scale inputs) by using the procedure in steps e to 1. The
only exception is that the DC Volts Standard is set for an
NOTE
the DC Volts Function,
Short the
output (in step i) of + 300mV instead of + 30mV.
o. (Step #5 and 6.) Remove the Digital Voltmeter and
the DC Volts Standard from the 3478A.
3478A's HI and LO INPUT Terminals and set the
instrument to the 3V Range.
p. Calibrate the 3V Range (applying zero and full scale
inputs) by using the procedure in steps e to 1. The only
exception is that the DC Volts Standard is set for an
output (in step i) of + 3V instead of + 30mV.
q. If no performance checks for the 3V range are to be
made, remove the DC Volts Standard and Digital
Voltmeter from the 3478A. Continue with step s.
r. If the performance checks for the 3V Range are to
be made, do the following:
1. Set the 3478A to the Internal Trigger Mode by
pressing the INT/TRIG button.
2. (Step #7.) Set the DC Volts Standard for a +
300mV output.
3. Using the Digital Voltmeter as the standard,
check and make sure the 3478A reading is within the
specified limits shown in Table 4-8.
4. (Step #8.) Set the DC Volts Standard for a + IV
output. Check the reading.
5. (Step #9.) Apply -IV to the 3478A by reversing
the input leads. (Leave the leads in that position for
the next step.) Check the reading on the multimeter
(per Table 4-8).
6. (Step #10.) Apply -3V to the 3478A by setting the
DC Volts Standard for a 3V output. Check the reading.
7. (Step #11.) Apply +3V to the 3478A by reversing
the input leads. Check the reading.
8. With + 3V applied to the 3478A, turn Autozero
off by pressing the blue Shift button and
INT/TRIG (AUTO/ZERO) button. Check the reading.
9. (Step #12.) Turn Autozero on by pressing the
blue Shift button
(AUTO/ZERO) button.
10. (Step #13.) With +3V still applied, select the
multimeter's 4 Digit Display mode by pressing the blue
Shift button and then the Uprange (4) button. Check
the reading.
11. (Step #14.) Select the 3478A's 3 Digit Display
by pressing the blue Shift button and
4-14
TM 11-6625-3071-14
Short the
then the
and then the INT/TRIG