Different types of ground-based detectors have been developed and deployed around the world to monitor and study cosmic ray (CR) variations. We have designed, constructed, and operated a small () three-layer multiwire proportional chamber detector for CR muon observations. The technical aspects of this detector will be briefly discussed. The ability of the detector to detect high-energy CR muons was established. The detector performed well in this sense and showed comparable results to our existing scintillator detector. The influence of atmospheric effects, mainly pressure and temperature, on the detected muons was determined. The corresponding coefficients were calculated and used to eliminate the pressure and temperature effects from the measured data.