Programming instructions

40 Chapter 4 Performance Verification Tests
of the DMM.
4. Set the range of the DMM to 100 mV. Wait five minutes for the DMM
to thermally stabilize.
5. Set MATH NULL on the transfer standard DMM.
6. Execute Trig SGL to trigger the NULL reading.
7. Remove the EMF cable leads from the DMM and connect them to the
HI and LO Input terminals 3458A under test. Connect the Guard
terminal of the voltage source to the guard terminal of the 3458A
under test.
8. Set the range of the 3458A under test to 100 mV. Wait five minutes for
the 3458A under test to thermally stabilize.
9. Set MATH NULL on the 3458A under test and execute Trig SGL to
trigger the NULL reading
10. REMOVE THE SHORTING STRAP FROM THE VOLTAGE
SOURCE HI and LO OUTPUT TERMINALS.
11. Connect the output of the voltage source to the HI and LO Input
terminals of the transfer standard DMM. With the DMM range set to
100 mV, set the output of the voltage source to 100 mV. Wait five
minutes for the transfer standard DMM to thermally stabilize.
NOTE: The thermal stabilization achieved for the 100 mV range is
present for the 1V and 10V ranges since these ranges use the same
relays. The range relays are opened for the 100V and 1000V ranges
and therefore, have no thermal impact on the measurement
12. Execute Trig SGL and read the output of the voltage source as
measured with the transfer standard DMM and record this reading in
the "Transfer Standard Reading" column of the DC VOLTAGE
TESTS test card.
13. Move the connection from the transfer standard DMM HI and LO
Input terminals to the HI and LO Input terminals of the 3458A under
test.
14. Execute Trig SGL and read the value as measured with the 3458A
under test and record this value in the "Unit Under Test Reading"
column of the DC voltage Test Record.
15. Repeat steps 11 through 14 for each of the remaining DC voltage test
points specified in Table 2 on the following page.