Measurements of the current noise and nonlinearity in the pyrolytic carbon films of 322 resistors are given. The resistances and the dimensions of the films both varied over a wide range. It is demonstrated that when the dimensions of the films are taken into account their noise and nonlinearity are highly correlated: the noise in a given film can therefore be used to estimate the nonlinearity, and conversely. In many groups of resistors of the same type the resistance change with a given applied voltage varied among resistors by a factor of more than 10, and the noise power for a given current through the resistors varied by a factor of more than 100.
In the measurements of nonlinearity the resistance changes were often very small, and, consequently, were easily masked by temperature effects. A measurement method was employed in which the resistors were placed in a balanced bridge, a short high‐voltage pulse was applied to the bridge, and the resistance change was determined from the bridge output voltage. With this technique it was possible to measure resistance changes of the order of 20 ppm with an accuracy of ±3 ppm.