An electrode-arc sensor (122, 124, 126) for measuring fluid data, comprising: a first electrode and a second electrode arranged substantially parallel and spaced from the first electrode to form a fluid gap therebetween for receiving a fluid stream, wherein the first electrode and the second electrode are configured to directly contact the fluid stream; a voltage source operatively connected to the first and second electrodes and configured to generate a voltage sufficient to induce an arc therebetween; a voltage sensor configured to detect voltage measurements across the first and second electrodes; and a controller operatively connected to the voltage source and voltage sensor, the controller configured to: command the voltage source to generate a voltage until the arc is induced; generate a time-series of voltage measurements from the voltage sensor; determine an arc lifetime and a breakdown voltage of the arc based on the time-series of voltage measurements; and determine a fluid speed and a fluid density of the fluid stream based on the time-series of voltage measurements, wherein the fluid speed is determined based on the arc lifetime and the fluid density is determined based on the breakdown voltage, wherein the breakdown voltage and the arc lifetime are compared to a fluid data model to determine the fluid speed and fluid density. a first electrode and a second electrode arranged substantially parallel and spaced from the first electrode to form a fluid gap therebetween for receiving a fluid stream, wherein the first electrode and the second electrode are configured to directly contact the fluid stream; a voltage source operatively connected to the first and second electrodes and configured to generate a voltage sufficient to induce an arc therebetween; a voltage sensor configured to detect voltage measurements across the first and second electrodes; and a controller operatively connected to the voltage source and voltage sensor, the controller configured to: command the voltage source to generate a voltage until the arc is induced; generate a time-series of voltage measurements from the voltage sensor; determine an arc lifetime and a breakdown voltage of the arc based on the time-series of voltage measurements; and determine a fluid speed and a fluid density of the fluid stream based on the time-series of voltage measurements, wherein the fluid speed is determined based on the arc lifetime and the fluid density is determined based on the breakdown voltage, wherein the breakdown voltage and the arc lifetime are compared to a fluid data model to determine the fluid speed and fluid density. command the voltage source to generate a voltage until the arc is induced; generate a time-series of voltage measurements from the voltage sensor; determine an arc lifetime and a breakdown voltage of the arc based on the time-series of voltage measurements; and determine a fluid speed and a fluid density of the fluid stream based on the time-series of voltage measurements, wherein the fluid speed is determined based on the arc lifetime and the fluid density is determined based on the breakdown voltage, wherein the breakdown voltage and the arc lifetime are compared to a fluid data model to determine the fluid speed and fluid density.