Sensor systems, sensors, and methods for detecting a presence and a phase of a medium on a surface are described. The sensor system has a power source providing a voltage; a sensing element in electrical communication with the power source, the sensing element including: two electrodes, wherein a gap is defined between the two electrodes, and a temperature measurement device disposed between the two electrodes; a fixed resistor in electrical communication with the power source and the sensing element; and a data acquisition system in electrical communication with the power source, the sensing element, and the fixed resistor. The sensor system measures the electrical resistance of the medium, and the temperature of the surface, and identifies the phase of the medium.