Reconciliation between Thermodynamics and Noise Measurements on Metal Film Resistors

The deviation of a resistor's $I-V$ curve from linearity as a result of Joule heating and its temperature coefficient of resistivity are shown to be sufficient to predict the low-frequency limiting spectral density of resistance fluctuations caused by spontaneous enthalpy fluctuations. The prediction agrees with previous experiments. Previous predictions that substantially exceeded measured noise in metal film resistors are shown to rely on incorrectly normalized current-jump data.