  The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter in
charge of the electron background rejection downstream of the cooling channel
at the international Muon Ionization Cooling Experiment. It consists of 2832
plastic scintillator bars segmented in 48 planes in an X-Y arrangement and uses
particle range as its main variable to tag muons and discriminate electrons. An
array of analyses were conducted to characterize the hardware of the EMR and
determine whether the detector performs to specifications. The clear fibres
coming from the bars were shown to transmit the desired amount of light, and
only four dead channels were identified in the electronics. Two channels had
indubitably been mismatched during assembly and the DAQ channel map was
subsequently corrected. The level of crosstalk is within acceptable values for
the type of multi-anode photomultiplier used with an average of
$0.20\pm0.03\,\%$ probability of occurrence in adjacent channels and a mean
amplitude equivalent to $4.5\pm0.1\,\%$ of the primary signal intensity. The
efficiency of the signal acquisition, defined as the probability of recording a
signal in a plane when a particle goes through it in beam conditions, reached
$99.73\pm0.02\,\%$.
