Question from the Customer:
I am using the Advanced Cable Tester v2 (ACTv2) to run a USB Type-C to USB Type-C cable test and I’m wondering how the cable tester calculates resistance values? It’s helpful to know as we verify our cables’ performance against standards. We’d also like to know which physical factors, like cable length, temperature, or connector wear, could affect the readings?
Here are the measurements that I observed:
Response from Technical Support:
Thank you for your question! Here is an overview of how cable resistance is measured, factors can can affect measurement results.
How the Advanced Cable Tester v2 Measures Cable Resistance
Thank you for your question! The Advanced Cable Tester v2 implements four-wire measurement for resistance measurements. A known current is passed through the cable, and the voltage difference is measured at two points. With Ohm’s Law, this voltage measurement is used for calculating the resistance values.
- For the wire measurements, current is passed through the indicated pins and/or the shells. The voltage is measured at the point where the connector interfaces with our module’s PCB. When multiple pins are part of the measurement, multiple points are measured. In this case, the lowest value is selected to account for contacts that may have higher resistance.
- The pin measurements are more complex. The current sink and measurement point must be the same pin, while the current source and other point of measurement is a group of pins. To find the most relevant and accurate reading, each pin in that group is tested, and the lowest resistance measurement is selected.
Measurement Factors
Cable length is not a factor in our measurements, as it is not included in the specification criteria. Additionally, temperature has not been found to significantly affect measurement results. The most impactful factors are contact quality, connector wear, and overall design.
We hope this answers your questions. Additional resources that you may find helpful include the following:
If you want more information, feel free to contact us with your questions, or request a demo that applies to your application.