Galvanic resistance is easily disturbed in the cheap usb cables.
Usb cable resistance meter.
Makerhawk usb multimeter usb voltmeter ammeter load tester usb voltage current pd battery power capacity charger digital type c meter tester color lcd display cable resistance qc2 0 3 0 4 0 mtk 4 1 out of 5 stars 63.
That sudden jump was coincident with my sneezing approximately 0 5 meter distant from the cable facing away from the cable.
Better quality usb cables are much more robust.
Makerhawk um34c usb meter tester voltage current bluetooth battery power charger voltmeter ammeter multimeter tester 1 44 inch color lcd display usb 3 0 type c cable resistance load impedance meter.
Supports usbc usb and resistance tests with microusb cables.
Usb tester um25c usb meter tester voltage current bluetooth battery power charger voltmeter ammeter multimeter tester 1 44 inch color lcd display usb 2 0 type c cable resistance load impedance mete 4 6 out of 5 stars 9 25 99 25.
There is an app for both android and windows you can install to log measurements and change some of the basic settings like brightness etc.
The rm3548 is a high precision portable resistance meter capable of measuring resistance levels from microohms to megaohms and is intended primarily for use in testing and maintenance of large equipment for example measuring the winding and weld resistances in large motors.
It seems a bit more accurate then some of the cheaper usb multi meters in this price range.
Look again at the usb cable in the 2 5 to 3 5 ohm range y axis expansion near the end at 9 75 min.
Riden um24 um24c usb 2 0 color lcd display tester voltage current meter voltmeter amperimetro battery charge measure cable resistance cod brand.
If you are using a regular cable max length of 5 meters for 2 0 and max length of 3 meters for 3 0 3 1 with an active cable then the maximum length for usb 2 0 is 25 meters about 82 feet and the maximum recommended length for usb 3 0 3 1 is 15 meters about 49 feet.
