基于双MCU的高精度低成本超声流量计

摘要

针对传统超声流量计精度低、功率损耗大的问题,研制了一种新型超声波流量计.该流量计采用高速CMOS计数器74AC161,选用133 MHz高精度,高稳定度频率振荡器,提高测量精度同时降低成本.采用环鸣法,设计阈值电路、过零电路,减小测量误差,提高测量精度、增强了抗干扰能力.实验结果表明:该超声流量计在计时方面具有高的准确度和可靠性,保证了流量测量精度,简化了电路设计,降低了设计成本,达到了预期设计要求.%A new kind of ultrasonic flowmeter system based on transit-time method was designed. The system used high-speed CMOS counter 74AC 161 and 133 MHz high-precision frequency oscillators to improve the accuracy of measurement and reduce the cost,and to overcome the shortcomings of low precision time measurement and high power dissipation of traditional ultrasonic flowinders. The accuracy improvement of measurement and anti-jamming capability enhancement were achieved by using the sing-around method,reasonable threshold circuit,and zero crossing comparator.The experiment results indicate that the expected design requirements of flowmeter are reached with high accuracy of timing and reliability, simplified design of measurement circuits and reduced design cost.