基于超声回波声压特性的外感式液位测量系统的设计

Design of External Level Measurement System Based on Ultrasonic Echo Sound Pressure

针对传统液位测量系统在复杂环境下对密闭容器内液位进行测量时测量精度低、可靠性差等问题。设计了一种外感式液位测量系统。该系统通过比较容器内液体液面上下方超声回波声压的不同,实现液位的测量。硬件电路采用增益可控的仪表放大器AD603辅以高速运算放大器AD818组成超声波驱动电路,实现了不同幅值的激励信号的输出;利用峰值检波电路对回波信号进行检波处理。通过实验验证,该系统能有效的测量密闭容器内的液位,测量误差小于3 mm。

In view of the traditional liquid level measurement system in a complex environment the liquid level in a closed container is measured with low measurement accuracy and poor reliability,an external level measurement system is designed.The system compares the sound pressure of the ultrasonic echoes,that is the echo above the liquid level with the echo below the liquid level in the container to achieve liquid level measurement.The hardware circuit uses the controllable gain in instrumentation amplifier AD603 and high-speed operational amplifier AD818 to output the excitation signal of different amplitudes.The peak detection circuit is used to detect the echo signal.The experimental results show that the system can effectively measure the liquid level in the sealed container.The measurement accuracy is less than 3 mm.