  In this work, time series analysis techniques are used to analyze sequential,
equispaced mass measurements of a Si density artifact, collected from an
electromechanical transducer. Specifically, techniques such as Power Spectral
Density, Bretthorst periodogram, Allan variance and Modified Allan variance can
provide much insight regarding the stochastic correlations that are induced on
the outcome of an experiment by the measurement system and establish criteria
for the limited use of the classical variance in metrology. These techniques
are used in conjunction with power law models of stochastic noise in order to
characterize time or frequency regimes by pointing out the different types of
frequency modulated (FM) or phase modulated (PM) noise. In the case of phase
noise, only Modified Allan variance can tell between white PM and flicker PM
noise. Oscillations in the system can be detected accurately with the
Bretthorst periodogram. Through the detection of colored noise, which is
expected to appear in almost all electronic devices, a lower threshold of
measurement uncertainty is obtained and the white noise model of statistical
independence can no longer provide accurate results for the examined data set.
