New Development Of Ultrasonic Level Meter

Distance measurement by ultrasonic is an effective and non-contact ranging method, and it has already extensively applied to river bits, chemical and pharmaceutical, food processing, oil, sewage treatment, and other various occasion needing level measurement. With the application of IC technology, the sensor technology and signal processing technology, liquid level detection technology has made a rapid development and progress, and all kinds of well-found, high precision, large range of integration, miniaturization, intelligent ultrasonic level meter continuously emerge. However, in domestic companies, the ones who can research and develop the productions independently are exiguous, and their level is not very high. Under this circumstances, developing a kind of high stability, high precision, low cost of ultrasonic level meter is quite necessary.Firstly, the feasibility analysis of using the method of impulse transmission is done after the introduction of development history and trend indicator of the level meter in brief, and this thesis shows overall hardware block diagram of the system, based on a mass of consultion and reference of technical information and papers.Scondly, the hardware and software designation of ultrasonic level meter are introduced emphatically in this paper. In the system, the cybernetics core of the ultrasonic level meter designed by this subject is C8051F020 single chip microcomputer. The hardware of the ultrasonic level meter in this subject is discussed in detail, which focus on the design of the ultrasonic transmitter circuit, echo signal receiving circuit, trigger circuit, display and keyboard circuit, and other hardware circuit; The software is written mostly used in assembly language, which contains data acquisition and calculation, data conversion and filtering,systematic anti-interference and the logic functions of the control part.Finally, this paper analyzes the influences of the ultrasonic ranging by temperature, humidity, hardware circuit and the air disturbance, puts forward the measures to solve these interference factors, and makes compensation correspondingly. By analyzing the experimental data and calculation, the technical indexs of the whole machine are designed basically reached the requirements.