  The gas detector glass resistivity parallel chamber (GRPC) is proposed to use
in the Hadron calorimeter (HCAL), the read-out system is based on the
semi-digital system, then the charge information from GRPC is needed. To better
understand the charge comes out from GRPC, we started from cosmic ray test to
get the charge distribution and then study the induced charge distribution on
the collection pad, after successfully compared with the prototype beam test
data at CERN (European Council for Nuclear Research), the process was finally
implanted into the Geant4 based simulation for future study.
