A Comparison of the Noise and Voltage Coefficients of Precision Metal Film and Carbon Film Resistors

Measurements of the current noise and voltage coefficient are given for metal film and carbon film resistors. In general, the noise power in the metal resistors was less than that in the carbon by a factor of 103, although a few of the former type were very noisy. For many typical applications in and below the audio spectrum the current noise in a large fraction of the metal resistors will be smaller than thermal noise even at rated dissipation. The voltage coefficients of the metal resistors were less than those in the carbon by a factor of about 10; in most units of the former type the coefficienats were less than 3 X 10--5per cent/volt, and in a few units they were less than I X 10--6per cent/volt. Voltage coefficients of both signs were found in the metal resistors, while all of them were negative in the carbon resistors.