I am using an E 4990A. When I use coax cable extensions to reach a measurement location, the position of the cables will change my readings.
Do all 4 cables need to have the shields tied together at the point of measurement? What are the best cables to use?
These are low impedance measurements (a few hundred ohms)
Hi,
Basically we don’t recommend our customer to fabricate own test lead/fixture. The terminal connector of the extension cable/fixture which is used to connect to the impedance analyzer has to be in 4-Terminal Pair configuration. The selection of appropriate test fixtures and cables as well as the techniques for obtaining the optimum DUT connection configuration are important for maximizing the total measurement accuracy. Please refer to chapter 3 of the Impedance Measurement Handbook for more detail about the benefits of various terminal configurations. http://literature.cdn.keysight.com/litweb/pdf/5950-3000.pdf
The adapter selection should be set to 0 m/ 1 m/ 2 m properly in accordance with the defined cable length of the test leads. The adapter setup is valid for the Keysight-specified four-terminal pair test leads/fixtures only (such as the 16048G/H, 16451B, etc.) Thus, the adapter setup cannot be applied to non-Keysight test leads, such as ordinary BNC cables and user-fabricated test leads. The Keysight four-terminal pair impedance analyzer has the adapter setup data memorized at factory, and the measurement accuracy for 0 m/ 1m/ 2 m cable length is verified by the performance tests. Please note that when the data of the extended cable mismatch the data of E4990A adapter setup, some errors might occur such as “Bridge Unbalanced”.
Please use the supported test leads (16048G/H) if possible. If you really need to fabricate own test lead/fixture, it is recommended to make it as short as possible and employ the coaxial cable as shown in Figure 3-11 on page 3-11 Of the Impedance Measurement Handbook. In this case, we cannot guarantee the performance of the measurements. Please set to the closest length for the adapter setup and perform Open/Short/Load compensation. For more information, please refer to section 4.6.4 Non-Keysight test cable and user-fabricated test fixture of Impedance Measurement Handbook.
Best Regards,
Raymond
Hi -
Moving your thread to the LCR / Impedance Analyzer forum for traction.
Thanks,
Jill