Keithley 7999-2, Instruction Manual

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Service Information 4-3
Performance verification
The following paragraphs discuss performance verification procedures for the Model
7999-2, including channel resistance, contact potential, and channel-to-channel and common-
mode isolation.
CAUTION Contamination will degrade the performance of the card. To avoid
contamination, always grasp the card by the cover; do not touch the
connectors.
NOTE Failure of any performance verification test may indicate that the multiplexer card is
contaminated. See “Handling and cleaning precautions” earlier in this section for
information on cleaning the card.
Environmental conditions
All verification measurements should be made at an ambient temperature between 18˚ and
28˚C, and at a relative humidity of less than 70%.
Recommended equipment
Table 4-1 summarizes the equipment necessary for performance verification, along with an
application for each unit.
Table 4-1
Recommended verification equipment
Description Manufacturer/Model Specifications Test
Digital Multimeter
Nanovoltmeter
Electrometer
Test Lead Sets (2)
Low Thermal Cable
Triax Cable Keithley 2010
Keithley 2182
Keithley 6517A
Keithley 1681
Keithley 2107-4
Keithley 237-ALG-2 10
Ω
range, 60ppm
10mV range, 50ppm
2G
Ω
range, 0.225%
Banana plug/clips
Low thermal/lugs
Triax/clips
Channel resistance
Contact potential
Isolation
Channel resistance
Contact potential
Isolation