【摘要】 基于超声技术和复杂可编程逻辑器件(CPLD)实现对两路同频超声传输过程中不仅是半个周期以内的相位差,而且大于半个周期乃至多个半周期的相位差的检测,仿真实现了微量气体浓度宽量程范围的检测,为基于超声技术的微量气体浓度检测的量程拓展提供了技术借鉴。更多还原

【Abstract】 Based on ultrasonic technology and complex programmable logic device(CPLD),the phase difference detection of less than or more than half a cycle,and even spanning more semi-cycles,is carried out in the transmission process of two channels of ultrasonic.Also the wide-range micro-concentration gas test is achieved by simulation.This research provides a technical reference for the measuring range exp-ansion of micro-concentration gas detection based on ultrasonic technology.更多还原