A method monitors a line for changed ambient conditions. The line has a measuring line with a predetermined length and a measuring conductor surrounded by insulation having a known dielectric constant. In the method, an analog signal having a predetermined frequency is generated, the signal is divided into a reference signal and an operating signal, the operating signal is fed into the measuring conductor, a return signal obtained from the operating signal is combined with the reference signal and by a phase shift between the reference signal and the return signal, a measure is determined for the changed condition, particularly for a temperature change.

Systems and methods for identifying a location of a thermal event detected by a temperature sensing tape are provided. In some embodiments, the temperature sensing tape can include a resistive ladder with parallel resistors between a plurality of temperature sensing elements to create voltage dividers, and unique analog output voltages can correspond to different ones of the plurality of temperature sensing elements being activated. In some embodiments, pulses injected into and reflected by the temperature sensing tape can be used detect a distance to a location where a triggering event is detected.