Study On The Method Of GAS Temperature Measurement Based On Ultrasonic Technology

On the purpose of realizing fast and accurate measurement of gas temperature, a scheme of measuring gas temperature using ultrasonic is proposed in this paper based on further studying current research of transient gas temperature measurement at home and aboard. Firstly, utilizing aerodynamics, a mathematical model of temperature measurement using ultrasonic is established according to ideal gas status equation. The whole system is designed found on model of temperature measurement and principle of realizing fast measurement. The system consists of the transmitting and receiving ultrasonic, measuring pressure, collecting data, and controlling of Single Chip Micyoco and PC mainly. Design and installation of ultrasonic sensor is accomplished at the part of transmitting and receiving ultrasonic. It introduces the principle, classification and composition of piezoelectric ultrasonic sensor used. Design of polysilicon high temperature pressure sensor is accomplished at the part of measuring pressure. It consists of analyzing sensitivity, designing chip figure, designing fabrication skill and testing performance of pressure sensor. At the same time, in order to meet the need of fast measurement, pipeline analog-to-digital converter ADS800 is selected to convert analog signal of pressure. It mainly establishes the measurement of time-of-flight using digital phase-shift technology at the part of collecting data based on field programmable gate array. To solve the problem of storing data falsely, a scheme of a double pulse-latching scheme is presented. Single Chip Micyoco and PC are used to monitor system operating and process data, then measurement results are displayed and printed. Another job is to design systematic software. Module design is adopted in order to compile and debug the program. It mainly consists of display module, menu module, dealing with key-values module, dealing with parameters module and measurement module. In order to validate the feasibility of system and scheme, system of ultrasonic temperature measurement established is simulated at Matlab. The results of experiment show that operation of system is steady and precision of measurement is very high. The purpose of fast and accurate measurement of gas temperature is realized.