  We present an internal consistency test of South Pole Telescope (SPT)
measurements of the cosmic microwave background (CMB) temperature anisotropy
using three-band data from the SPT-SZ survey. These measurements are made from
observations of ~2500 deg^2 of sky in three frequency bands centered at 95,
150, and 220 GHz. We combine the information from these three bands into six
semi-independent estimates of the CMB power spectrum (three single-frequency
power spectra and three cross-frequency spectra) over the multipole range 650 <
l < 3000. We subtract an estimate of foreground power from each power spectrum
and evaluate the consistency among the resulting CMB-only spectra. We determine
that the six foreground-cleaned power spectra are consistent with the null
hypothesis, in which the six cleaned spectra contain only CMB power and noise.
A fit of the data to this model results in a chi-squared value of 236.3 for 235
degrees of freedom, and the probability to exceed this chi-squared value is
46%.
