Programming instructions

Chapter 4 Performance Verification Tests 49
a. Note - At 10 MΩ, leakage current from the Sense leads introduce additional
uncertainty in the measurement. This uncertainty, however, is accounted for
in the published performance test limit. For best accuracy and consistency
across calibration sites and environments, Test 7 can be performed using a
2-wire ohms measurement. The performance test limit remains the same for
both 4-wire and 2-wire measurements of 10 M
Ω.
10. After all OHMF gain tests have been performed, calculate and record
in the column provided, the difference (absolute value) between the
transfer
standard DMM reading and the unit under test reading for
each of the test points.
11. If any of the differences calculated are beyond the specified limits,
refer to Chapter 3 to make adjustments.
12. Disconnect the resistance standard from the 3458A input terminals.
Frequency Counter Performance Tests
Required Equipment The following equipment is required for testing the frequency counter
performance of the 3458A.
• Stable frequency source (Keysight 3325A Frequency Synthesizer
or equivalent)
• Shielded test leads, BNC to dual banana plug (such as
Keysight 11001-60001)
Preliminary Steps 1. Verify that the frequency source is properly warmed up.
2. The 3458A requires a 4-hour warm-up period. If this has not been
done, turn the instrument ON and allow it to warm up before
pro
ceeding.
3. If the instrument self test has not been run, make certain all inputs are
disconnected and execute the TEST function. The display must read
"S
ELF TEST PASSED".
Table 6. OHMF Gain Performance Tests
OHMF Gain Test
Number
Source and DMM
Range
Source Output
110 Ω 10 Ω
2 100 Ω 100 Ω
31 kΩ 1 kΩ
4 10 kΩ 10 kΩ
5 100 kΩ 100 kΩ
61 MΩ 1 MΩ
7
a
10 MΩ 10 MΩ