Conventional CO Gas Detector AW-CCO851 The AW-CCO851 gas detector is designed for single station use or for connecting to fire alarm or security alarm panel. It is intended to detect leakage of natural gas (methane gas), town gas, and bottled gas (propane gas), coal gas or carbon monoxide. The gas detector can be mounted high (for methane gas) or low (for propane (LPG) gas).