Abstract: A cathodic protection system comprising remote test units for measuring various voltages and currents at remote locations on a cathodically-protected pipeline. The remote test units may comprise a processor configured to store measurements taken with the voltmeter and a wireless transceiver for communicating with other test units and/or a Web server or host computer in a daisy-chain or mesh radio configuration. The remote test units may comprise an instant-off switch which electrically connects the pipeline with a buried protected coupon of the same material as the pipeline, and a voltmeter configured to measure the instant-off potential of the protected coupon when the switch is opened. The test units may also comprise a millivoltmeter configured to measure a voltage across a critical bond current shunt resistor and an ammeter configured to measure AC and DC current flowing between the pipeline and the protected coupon with the instant-off switch is closed.