  India-based Neutrino Observatory (INO) facility is going to have a 50 kton
magnetized Iron CALorimeter (ICAL) detector for precision measurements of
neutrino oscillations using atmospheric neutrinos. The proposed ICAL detector
will be a stack of magnetized iron plates (acting as target material)
interleaved with glass Resistive Plate Chambers (RPCs) as the active detector
elements. An RPC is a gaseous detector made up of two parallel electrode plates
having high bulk resistivity like that of float glass and bakelite. For the
ICAL detector, glass is preferred over bakelite as it does not need any kind of
surface treatment to achieve better surface uniformity and also the cost of
associated electronics is reduced. Under the detector R&D efforts for the
proposed glass RPC detector, a few glass RPCs of 1m X 1m dimension are
fabricated procuring glass of ~ 2 mm thickness from one of the Indian glass
manufacturers (Asahi). In the present paper, we report the characterization of
RPC based on leakage current study, muon detection efficiency and noise rate
studies with varying gas compositions.
