Abstract: An electric arc furnace (EAF) including a raw material container, a set of electrodes, a set of electrical potential transformers, and a reference signal verification device. The set of electrodes are configured to be controllably extended toward the raw material container. The set of electrical potential transformers are correspondingly coupled to the set of electrodes. The reference signal verification device is configured to carry out the steps of reading a reference signal value coming from the raw material container; comparing the reference signal value to an approximated value; and determining that there is a loss of the reference signal if the reference signal value is not within a predetermined amount of the approximated value.