  The SoLid experiment has been designed to search for an oscillation pattern
induced by a light sterile neutrino state, utilising the BR2 reactor of
SCK$\bullet$CEN, in Belgium. The detector leverages a new hybrid technology,
utilising two distinct scintillators in a cubic array, creating a highly
segmented detector volume. A combination of 5 cm cubic polyvinyltoluene cells,
with $^6$LiF:ZnS(Ag) sheets on two faces of each cube, facilitate
reconstruction of the neutrino signals. % The polyvinyltoluene scintillator is
used as an $\overline{\nu}_e$ target for the inverse beta decay of
($\overline{\nu}_e + p \rightarrow e^{+}+n$), with the $^6$LiF:ZnS(Ag) sheets
used for associated neutron detection. Scintillation signals are read out by a
network of wavelength shifting fibres connected to multipixel photon counters.
Whilst the high granularity provides a powerful toolset to discriminate
backgrounds; by itself the segmentation also represents a challenge in terms of
homogeneity and calibration, for a consistent detector response. The search for
this light sterile neutrino implies a sensitivity to distortions of around
$\mathcal{O}$(10)\% in the energy spectrum of reactor $\overline{\nu}_e$.
Hence, a very good neutron detection efficiency, light yield and homogeneous
detector response are critical for data validation. The minimal requirements
for the SoLid physics program are a light yield and a neutron detection
efficiency larger than 40 PA/MeV/cube and 50 \% respectively. In order to
guarantee these minimal requirements, the collaboration developed a rigorous
quality assurance process for all 12800 cubic cells of the detector. To carry
out the quality assurance process, an automated calibration system called
CALIPSO was designed and constructed.
