To verify the proper operation of a catalytic combustible gas sensor, it is necessary to periodically apply a gas of known concentration to the sensor. This is usually done manually at the site with gas supplied from a small lecture bottle. As the sensor reacts to the calibration gas, adjustments are made to the monitoring system to bring its calibration into agreement with the known concentration of gas. At times, sensors are mounted in inaccessible locations, requiring expensive catwalks or scaffolding to reach them. The Automatic Remote Gas Calibrator (ARGC) allows the calibration gas to be applied to the catalytic bead sensor from easily accessible locations. The ARGC is used for blocking ambient air and redirecting methane to the catalytic sensor for calibration or testing sensor accuracy. The ARGC tests or calibrates the General Monitors catalytic sensor with 50% LEL methane. The unit is capable of calibrating gas at wind velocities up to 50 mph. Note: the RGC (P/N 80153-1), used manually with a pressure regulator (P/N 80147-1), is suitable for calibrating with any light hydrocarbon.