  The systematic uncertainty on the correspondence between muon range and
energy is developed for the NOvA neutrino experiment. NOvA consists of two
detectors, the Near Detector at Fermilab and the Far Detector in northern
Minnesota. Total errors are developed for the Near Detector, with its Muon
Catcher treated separately, the Far Detector, and all combinations of
correlated and uncorrelated errors between these three detectors. The absolute
errors for the Near Detector (1.0%), the Far Detector (0.9%), and the fully
correlated error shared by them (0.9%) are strongly dominated by Geant4's
treatment of the Bethe density effect. At the Near Detector, the next biggest
uncertainty is from stray hits caused by neutron capture pile-up. Other
contributions are marginally significant, with the biggest, in descending
order, being due to external measurements of the mean excitation energies of
elements, detector mass accounting, and modification of energy loss by chemical
binding. For the Muon Catcher, the absolute error is expressed as an offset
instead of a percentage: 21 MeV. The density effect (at higher energies) and
neutron capture pile-up (at lower energies) are the strongly dominant errors.
The relative error between the Near and Far Detectors is 0.4% and is strongly
dominated by neutron capture pile-up at the Near Detector, with a subdominant
contribution from detector mass accounting.
