Ultrasonic Level Of Development,

Recently, with the development of science and technology, level measurement plays an increasingly important role in the industry, agriculture as well as in people's daily life. In the level measurement fields, the mostly widely used measurement method is the ultrasonic level meter for non-contact detection. Compared with other methods, this method has many advantages such as cheap, simplicity, high real-time, flexible application, and strong adaptability, not affected by light, dust, smoke and electromagnetism. Currently, many types and quantities of domestic ultrasonic level measuring products have been manufactured, but the development of ultrasonic product is obviously lagged to advanced foreign research in this field. Accordingly, it is still, even in the future, one of the challenging and significant problems in ultrasonic field to develop the high performance and low cost ultrasonic level meter. After adequate research and access to a large number of domestic and foreign literature data, as well as analysis the quality of ultrasonic and comparison of various level measurement instrument, advanced ultrasonic level meter was developed.The design goal is to improve its functions under the premise of simplicity and reasonable cost. In the system, 16-bit ultra-low-power microcontroller MSP430F149 controls the entire system which based on the principle of ultrasonic time difference method. This paper designs high frequency pulse driving circuit to raise driving-ability greatly, according to the ultrasonic characteristic of index attenuation when it's spreading because we need to measure longer distance. The signal processing modular consist of preamplifier circuit, band-pass filter circuit, noise suppression circuit, peak value sampling circuit, automatic gain control circuit, threshold detection circuit. In addition, temperature compensation is taken to enhance precision, as well as anti-interference measure is used in both software and hardware in order to satisfy the reliability and stability of ultrasonic level meter.In the study, it accomplishes the research in theory, the design in hardware and software, the system debugging, ultrasonic sensor calibration, measurement data analysis, in addition error correction. Keyboard and LCD are designed for convenient field operation, also multi communication interfaces are provided for on-line monitoring level and real-time processing. Software includes MCU Program and monitoring software of host computer. The results show that the instrument works stably and reliably, and has high measurement precision. This kind of ultrasonic level meter meets design requirement, so that it has huge market potential and will apply widely.