Keysight U2741A, Service Manual

Page: 30 / 54

16 U2741A USB Modular 5.5 Digits Digital Multimeter Service Guide
2 Performance Test Calibration
Performance Verification Tests
Zero offset verification
This test is used to check the zero offset performance of the
instrument. Verification checks are only performed for those
functions and ranges with unique offset calibration
constants. Measurements are checked for each function and
range as described in the procedure on the next page.
Zero offset verification test
1
Connect the Shorting Plug to the voltage HI and LO input
terminals. (see
“Input connections" on page 13 ). Leave the
current inputs open.
2
Select each function and range in the order shown in the
table below. Make a measurement and observe the result.
Compare the measurement results to the appropriate test
limits shown in
Table 2- 2 .
N O T E
Note that resistance measurements use the Null math function (Null
reading taken with test leads connected together) to eliminate test lead
resistance.
Table 2-2 Zero offset verification test
Input Function
[1]
Range Quick check Error from nominal
1 year
Open
DC Current
10 mA Q ±1.5 µA
Open 100 mA ±5 µA
Open 1 A ±70 µA
Open 2 A ±140 µA