基于单片机的超声波流量计,1. 研究了时差法超声波流量计的测量原理，对超声波在流体中传播特性及超声波换能器的特性及安装选择进行了深入研究-Ultrasonic flowmeter based on single-chip, 1. Study of the time difference method of measuring ultrasonic flowmeter principle of ultrasonic propagation in the fluid and the ultrason