Comparison of DMM characterization methods based on RMS noise and standard deviation noise

Analogue to digital converters (ADCs) are very important component of digital multimeters for defining their accuracy. Along with ADC's specifications that are described in this paper, there are also “real” parameters that describe how DMMs and ADCs fare in real world with the presence of noise. Those parameters include, but are not limited to signal-to-noise ratio, effective resolution, effective bits, noise free resolution, etc. The purpose of this paper is to test and compare different DMMs in 6.5-7.5 digit range using the specific formula for effective resolution.