Real time multi-channel gas leakage monitoring system using CPLD chip

A multi-channel gas leakage monitoring system was designed and fabricated by using complex programmable logic device (CPLD) for monitoring and controlling the leakage of natural gas from the natural gas supplying pipeline under the ground. A planar structure gas sensor was attached under safeguard steel plates of natural gas supplying pipeline, and the local monitoring system which networked with a number of gas sensors received the signals from the attached gas sensors. The monitoring system was implemented by using CPLD chip to reduce the developing time for the system and the system size. The time sharing multi-channel system received the input signals from individual gas sensors at divided periodic times and signal-processed sequentially. The fabricated system could monitor the local area of natural gas pipeline with the miniature monitoring system.