基于STM32的便携式溶解氧测量仪设计(论文11000字)
摘要：溶解氧是指溶解于水中分子状态的氧，关系到生活的方方面面。水中溶解氧的多少决定了水体的理化性质和生物活性，是水质的一项重要指标，溶解氧的检测对于水产养殖以及环境监测的发展都具有重要意义。
本文介绍了溶解氧的测量方法，在研究了极谱式溶解氧的测量原理的基础上，依据电流法溶解氧测量原理。使用STM32单片机识别电化学传感器上的电信号来测量溶解氧含量。同时通过外部存储器预先校正盐度以及大气压值从而减少测量结果的误差，并对温度进行软件补偿。
为了更快速的获得测量结果，本文使通过增加储能电容来预先给传感器放电。该储能电容在系统断电后可以给传感器预先提供一定量的极化电压；在溶解氧仪对水体实时监控的时候，测量系统通电前被测水体已经通过储能电容的放电获得一定的电压，可以大幅减少极化电压上升到合适区间的时间。
本文通过合理的设计硬件电路与软件流程使得系统结构非常稳定，测量也十分精确。硬件电路主要设计了电源电路，传感器测量电路和显示驱动电路；软件流程的设计稳定流畅，程序编写部分明确简洁，方便调试。
本文设计的溶解氧仪的测量范围为：0 — 20.00 mg/L，分辨度为：0.01 mg/L。对制作的样品，对比实验结果表明本文设计的溶解氧测量仪操作简单方便简易方便，响应速度快，性能稳定，精度高，可重复性好，实用性强。
关键词：溶解氧；STM32；电流法；响应时间
Design of Portable Dissolved Oxygen Meter
ABSTRACT: Dissolved Oxygen refers to the Oxygen Dissolved in the water molecular state, related to all aspects of life. Of dissolved oxygen in water for water bodies of physical and chemical properties and biological activity, is an important indicator of water quality, the detection of dissolved oxygen in aquaculture and environmental monitoring is significant to the development.
Dissolved oxygen measuring method has been introduced in this paper, after studying the polarographic type based on the principle of the measurement of dissolved oxygen, according to the current method of dissolved oxygen measurement principle.Use of STM32 MCU to identify the electrical signals on the electrochemical sensor to measure dissolved oxygen content. At the same time by the precorrection salinity and atmospheric pressure value so as to reduce the error of the measurement results, and software for temperature compensation.
In order to more quickly get the measurement result, this paper made by increasing the energy storage capacitor discharge to advance to the sensor. After the energy storage capacitor in the power system can provide a certain amount of polarized voltage to the sensor prior; When dissolved oxygen instrument for real-time monitoring of water, water to be tested prior to power measurement system has been obtained from the energy storage capacitor discharge voltage, can significantly reduce polarization voltage up to the appropriate interval of time.
In this article, through reasonable design of hardware circuit and software process makes the system structure is very stable, is also very accurate measurement. The design of hardware circuit is mainly the power circuit, sensor circuit and display driver circuit; The design of the software process stability is fluent, part program writing clear and concise, convenient debugging.
The measuring range of the design of dissolved oxygen instrument for: 0-20.00mg/L, the resolution is: 0.01 mg/L. To make samples, contrast experiment results show that the design of the dissolved oxygen meter operation is simple and convenient and simple and convenient, fast response speed, stable performance, high precision, good repeatability, strong practicability.
Key words: dissolved oxygen;STM32;Current method; the response time
目 录
第一章 绪论 1
1.1 测量溶解氧的意义 1
1.2 国内外对于溶解氧测量的研究现状 1
1.3 溶解氧的测量方法 1
1.4 影响溶解氧测量的因素 2
第二章 溶解氧测量仪的设计原理 4
2.1 测量仪的应用范围 4
2.2 测量仪的传感器 4
2.3 传感器的测氧原理 4
第三章 减少溶解氧测量仪响应时间的方法研究 5
3.1 溶解氧测定响应时间分析 5
3.2 氧电流处理电路分析 5
3.2.1 传统氧电流处理电路 6
3.2.2 新型氧电流电路设计 6
3.3 溶解氧测定响应时间对比结果 7
第四章 溶解氧测量仪的硬件电路设计 9
4.1 系统硬件设计的总体结构 9
4.2 STM32F103微处理器介绍 9
4.2.1 STM32F103系列微处理器的结构特性 9
4.2.2 STM32F103系列微处理器的总线矩阵 10
4.3 电源电路设计 10
4.4 传感器测量电路设计 11
4.5 控制电路以及A/D转换电路设计 12
4.6 显示驱动电路设计 13
第五章 溶解氧测量仪的软件程序设计 14
5.1 系统软件的总体设计 14
5.2 软件对温度、盐度以及大气压的补偿 14
第六章 实验结果与分析 15
6.1 溶解氧测量仪精确度分析 15
6.2 溶解氧测量仪稳定性分析 16
第七章 总结和展望 17
参考文献 18
致谢 19
|
