  The UA9 Experiment at CERN-SPS investigates channeling processes in bent
silicon crystals with the aim to manipulate hadron beams. Monitoring and
characterization of channeled beams in the high energy accelerators environment
ideally requires in-vacuum and radiation hard detectors. For this purpose the
Cherenkov detector for proton Flux Measurement (CpFM) was designed and
developed. It is based on thin fused silica bars in the beam pipe vacuum which
intercept charged particles and generate Cherenkov light. The first version of
the CpFM is installed since 2015 in the crystal-assisted collimation setup of
the UA9 experiment. In this paper the procedures to make the detector
operational and fully integrated in the UA9 setup are described. The most
important standard operations of the detector are presented. They have been
used to commission and characterize the detector, providing moreover the
measurement of the integrated channeled beam profile and several functionality
tests as the determination of the crystal bending angle.
  The calibration has been performed with Lead (Pb) and Xenon (Xe) beams and
the results are applied to the flux measurement discussed here in detail.
