A novel surface acoustic wave (SAW) sensor array based on wireless communication\nnetwork is prepared. The array is composed of four SAW sensors, a wireless communication\nnetwork module, and a global positioning system (GPS) module. The four SAW sensors\nof the array are coated with triethanolamine, polyepichlorohydrin, fluoroalcoholpolysiloxane,\nand L-glutamic acid hydrochloride to detect hydrogen sulfide (H2S), 2-chloroethyl ethyl sulfide\n(CEES), dimethylmethylphosphonate (DMMP), and ammonia (NH3) at film thicknesses of 50â??100 nm.\nThe wireless communication network module consists of an acquisition unit, a wireless control unit,\nand a microcontroller unit. By means of Zigbee and Lora technologies, the module receives and\ntransmits the collected data to a PC work station in real-time; moreover, the module can control\nthe sensor arrayâ??s working mode and monitor the working status. Simultaneously, the testing\nlocation is determined by the GPS module integrated into the SAW sensor array. H2S, CEES, DMMP,\nand NH3 are detected in 300 m at different concentrations. Given the practical future application\nin environment in the future, the low, safe concentrations of 1.08, 0.59, 0.10, and 5.02 ppm for H2S,\nCEES, DMMP, and NH3, respectively, are detected at the lowest concentration, and the sensitivities\nof different sensors of the sensor array are 32.4, 14.9, 78.1 and 22.6 Hz/ppm, respectively. With the\nobtained fingerprints and pattern recognition technology, the detected gases can be recognized.
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