摘 要:量熱儀是能源生產和能耗企業必備的重要測量儀器,其測量精度直接影響著經濟效益。為提高量熱儀的測量精度,并實現量熱儀的網絡通信功能,設計一種基于S3C2410的恒溫式自動量熱儀,給出以石英溫度傳感器HTS-206為核心的溫度測量電路。利用CS8900A實現了網絡通信功能,確定了系統總體結構,給出了系統的軟件流程圖。結果表明,該設計能夠達到GB(T)213-2003標準,實現量熱儀的高精度測量。
關鍵詞:量熱儀; S3C2410; 石英溫度傳感器; HTS-206
中圖分類號:TN919; TP216.1文獻標識碼:A
文章編號:1004-373X(2010)15-0203-03
Design of Isothermal Automatic Calorimeter Based on S3C2410
JIANG Wei, ZHAO Shu-jun,XU Hang, DUAN Zhi-feng
(Physical Engineering Department, Zhengzhou University, Zhengzhou 450001, China)
Abstract: The calorimeter is an indispensable measurement instrument for energy production and energy consumption enterprises, and its precision of measurement directly influence on economic efficiency. An isothermal automatic calorimeter is designed based on S3C2410 in order to improve the measurement precision and realize the network communication of the calorimeter. A temperature measurement circuit of using quartz temperature sensor HTS-206 is given. The network communication is realized by making use of CS8900A, the overall structure of the system is determined, the flow chart of software is proposed. The experimental results prove that the deign can reach GB(T)213- 2003 standard and high-accuracy survey of the calorimeter can be achieved.
Keywords: calorimeter; S3C2410; quartz temperature sensor; HTS-206
0 引 言
量熱儀是能測定固、液態物質,如煤炭、火藥、粘度油、食品、飼料等可燃物質熱值的儀器。傳統的量熱儀受客觀因素影響較大,本文設計自動量熱儀可減少客觀因素的影響,實現數據的實時傳輸與實時處理,并使量熱儀具有網絡通信功能,能夠實現數據的網絡傳輸,并實現對量熱儀的遠程控制。
近年來隨著嵌入式技術的不斷成熟,其成本也不斷下降,本身所具有的規??勺?、擴展靈活、有較高的實時性和穩定性、系統內核小的優點逐漸凸現出來。
1 基本原理
恒溫式量熱儀通過氧彈法測量熱值。通過放在氧彈中的物質燃燒并使燃燒放出的熱量通過彈筒傳遞給水及儀器系統,再根據水溫的變化計算出物質的發熱量。其測量的基本框圖如圖1所示。
根據氧彈法測量的基本原理,發熱量計算公式如下[1]:
Qb.ad=[E(Tc-Tb+C)-(q1+q2)]m
式中:E為熱容量,單位:J/K;q1為點火熱,單位:J;
q2為添加物如包紙等產生的總熱量,單位:J;m為試樣質量,單位:g;……p>