An NIR-Based Probe for Submilligram Measurement of Solid Contaminants in Gas Pipelines

This paper suggests a new near-infrared (NIR)-based device to accurately measure the concentration of solid contaminants passing through gas–oil pipelines. It consists of a ring of NIR sources and receivers, which are evenly distributed across a cross section of the probe and connected to sources of lights and NIR spectrometers through multimode optical fibers. This allows a more accurate measurement of solid contaminants by capturing NIR light from the maximum volume in the probe, in addition to allowing image reconstruction of solid contaminants using image tomography techniques. The extracted data are processed by the principal component analysis, in order to keep only the most representative data of the spectrum. Extensive experimental results on non-diluted solid contaminants, the weight of which ranged from 0.212 to 0.717 g, demonstrate the capability of the device to measure the concentration of solid contaminants at submilligram scale, in addition to dealing with sand particles when they coexist with solid contaminants. A finite-element model is also provided in this paper to predict the behavior of the probe for different scenarios of the process. The corresponding simulation results indicate some overlaps with the experimental results.