Real-time multi-channel capacitive sensing system for cross bores detection and characterization

As many casualty incidents have been reported, gas-sewer pipe cross bore is recognized as a high-level risk and an increasing focus of the natural gas industry and the public. The sewer camera is the primary detection tool for the cross bore currently. However, it is limited by access to blocked and water-filled sewer pipes. Thus, there is an urgent need for developing an efficient and safe sensing system, which is not constrained by the challenging real field environment, to detect cross bores and prevent cross bore related incidents. A novel real-time multi-channel capacitive sensing system is proposed and developed to pass through the 2-inch gas pipe to perform the cross bore inspection nondestructively according to the changing material properties around the gas pipe. The designed capacitive sensing system is validated to have great performance to identify cross bores and estimate cross bore types based on the experimental results. This promising cross bore sensing system can be a good reference for the gas pipe industry.