  A highly granular hadronic calorimeter (HCAL) based on scintillator tiles
with individual readout by silicon photomultipliers (SiPMs) has been
constructed by the CALICE collaboration and has been tested extensively in
particle beams at CERN. The 7608 SiPMs coupled to scintillator tiles in the
approximately 1 cubic meter large calorimeter allow large sample studies of
behavior of these devices under varying voltage and temperature as well as
their saturation behavior. We also present detailed studies of the temperature
dependence of the calorimeter signal in muon and hadron beams. The calibration
of the full calorimeter using muons is discussed. In addition, a novel method
for calibration and detector studies using minimum-ionizing track segments in
hadronic showers, is explored.
