Data-probe cables are used to connect our reference electrode data-probes to the voltmeter in our data-loggers. When connected via a data-probe cable, the color of the band on a data-probe cable indicates to which side of the voltmeter the reference electrode will be connected.
If a black-band data-probe cable is used, the reference electrode data-probe will be connected to the negative side of the voltmeter. Such a data-probe cable will result in negative pipe-to-soil readings when the positive side of the voltmeter is connected to the pipe.

On the other-hand, if a red-band data-probe cable is used, the reference electrode data-probe will be connected to the positive side of the voltmeter. Such a data-probe cable will result in positive pipe-to-soil readings when the negative side of the voltmeter is connected to the pipe.