A novel chemical detector using cermet sensors and pattern recognition methods for toxic industrial chemicals

The development and evaluation of a novel gas sensing system intended for use on US Navy vessels is presented. The purpose of this sensor is to provide real-time detection and quantification of a wide range of known toxic chemicals including toxic industrial chemicals (TICs) and combustible or corrosive gases. The sensor system incorporates an array of ceramic-metal (cermet) gas microsensors with multivariate pattern recognition techniques and represents a rugged, light-weight, and low-cost solution to analysis problems that would otherwise need to be addressed with multiple conventional electrochemical sensors. The smart microsensor arrays are being developed by combining cermet electrochemical sensors utilizing cyclic voltammetry, with intelligent firmware and software to drive the sensors and analyze the data. The chemical microsensor architecture may be modified for detection selectivity of a variety of chemical species. The microsensor arrays have potential application for monitoring hazardous chemicals in the part-per-million to part-per-billion range in a variety of internal and external environments. The arrays sense analytes using pattern recognition techniques to determine the presence of vapors of interest. A test demonstrator has been developed with a four-sensor array, readout electronics, and system control software. The four-sensor array was exposed to 15 test vapors. The 15-analyte sources, including two blood agents, 10 TICs and three simulants were generated at five different concentrations in humid air. The cermet sensor array provided unique responses for the various analytes tested. Similar analyte types produced similar results. The sensitivity is sufficient to detect all the analytes at their respective exposure limits. A variety of feature selection and pattern recognition methods are being investigated for robust detection.