Automatic Testing System On The Calorific Value Of Fuel Gas Based On ARM

This paper designs an automatic test system of calorific value of fuel gas based on Embedded ARM &μC/OS-Ⅱsystem. The aim of this system is realizing automatic measurment of calorific value of gases by combine the principle of calorific value measurement by water-flow calorimeter and embedded technology. Using Pt100 thermal resitance as temperature sensor, MAX1148 as A/D conversion chip, impulse type water meter, and such related components, achieve precise measurement of temperature, pressure and flow, obtain necessary parameters from external flash storage through checking table interpolation, and thereby calculate out gross and low calorific value of fuel gas finally.The definition and development method of embedded system is introduced in this article, suitable hardware and software platforms are choosed, the core of the hardware LPC2134 and the core of the software platformsμC/OS-Ⅱare further studied, integral frame structure of the system is designed. On the hardware aspects, this article Cut the hardware,research and design the peripheral ciruit of LPC2134, temperature acquisition ciruit, pressure acquisition ciruit, impulse acquisition ciruit, human-machine interface circuit and some other important circuits, the anti-jamming performance is also analysised. As on software design, the designed system realize transplant the embedded real-time operation systemμC/OS-Ⅱto LPC2134, implementation of data acquisition, LCD display and keyboard scanning based onμC/OS-Ⅱ, through digital filter and watch-dog circuit design, the designed system is debugged successfully under the integrated development environment.This article successfully apply embedded technology to measurment of calorific value of gases by water-flow calorimeter,simplify the test steps, reduce dependence on the test operator and Reduce measurement error due to technological level of the operator and manual readings, improve the test efficiency.The experimental results show that the designed measurement system meet the requirment of measuring precission of calorimeter, have the features of simple structure, convenient manipulation and stability.