  The proposed magnetised Iron CALorimeter detector (ICAL) to be built in the
India-based Neutrino Observatory (INO) laboratory aims to detect atmospheric
muon neutrinos. In order to achieve improved physics results, the constituent
components of the detector must be fully understood by proper characterisation
and optimisation of various parameters. Resistive Plate Chambers (RPCs) are the
active detector elements in the ICAL detector and can be made of glass or
bakelite. The number of RPCs required for this detector are very large so a
detailed study is necessary to establish the characterisation and optimisation
of these RPCs. These detectors once installed will be taking data for 15-20
years. In this paper, we report the selection criteria of the glass electrodes
procured from Indian manufacturers. Based on the factors that deteriorate the
quality of glass the choice of electrode is made. The glass characterisation
studies include UV-VIS transmission for optical properties, SEM, AFM for
surface properties, WD-XRF, PIXE for determining the composition of glass
samples and electrical properties. Based on these techniques a procedure is
adopted to arrive at the best glass sample. We have done a second order check
on the quality of the fabricated glass RPCs. In this regard, the efficiency and
cross-talk of RPCs were measured. Results from Asahi and Saint Gobain glass
RPCs came out to be the best.
