《医用红外测温仪及温度补偿技术的研究》由会员分享，可在线阅读，更多相关《医用红外测温仪及温度补偿技术的研究（68页珍藏版）》请在金锄头文库上搜索。
1、医用红外测温仪及温度补偿技术的研究摘 要红外测温是目前最主要的非接触式测温方式之一。它具有响应速度快、测量范围宽、灵敏度高等优点，因而被广泛应用于各行各业。红外测温仪在用于体温检测时其测量温度范围应在24.0到45.0之间，精度要求为0.1。但目前使用的红外测温仪即使其精确度指标为1%，也远远达不到测量体温的精度要求。另外，在24.0到45.0的温度范围内，红外测温仪的测量精度很容易受外界环境温度的影响，导致其测量误差增大。同时红外测温仪的精度和稳定性很容易受到外界环境温度的影响。因此，减小外界环境因素对红外测温仪的影响具有十分重要的意义。本设计针对目前医用红外测温仪的现状，在查阅了大量国内外
2、文献的基础上，提出了一种新的环境温度的补偿方法。这种方法是根据热释电探测器的工作原理，以及被测物体与环境温度的差值作为参考量，根据其差值的大小确定补偿量的多少。通过数字测温芯片测量环境温度，采用软件补偿的方式，避免了以往用热敏电阻的缺点。在红外测温系统中，红外信号经过光学系统的汇聚、斩波器的调制和热释电探测器的接收后转变成频率为20 Hz的脉冲信号。此信号经过放大、滤波、整形和A/D转换成数字信号，再送到单片机中进行数据的处理、补偿和显示。在系统的设计过程中，采用Wave6000单片机仿真系统对单片机进行调试。为了保持各部分之间正确的时序关系，软件全部采用汇编语言来编写。系统经过定标和测试表明
3、：本系统在测量的精度和稳定性上有所提高。关键词 红外测温仪；热释电探测器；发射率；温度补偿；单片机；定标AbstractAs a main way of non-contact measurement,infrared measurement has many advantages,such as rapid reaction,wide measurement range and high sensitivity etc.Therefore,non-contact thermometry can be used in variety of spots.When infrared thermom
4、eter is used in medicine,The range of infrared thermometer is regulated between 24.0to 45.0and its precision must be 0.1when it is used in medicine.But most of infrared thermometer couldnt achieve this regulation.Meanwhile,in this temperature range,the precision of infrared thermometer can be greatl
5、y affected by ambient temperature.The error will increased greatly too.After looked up lots of data and realized the defect of infrared thermometer in medicinal scopes,a new compensatory way on environmental temperature is presented in this paper.This new way bases on the principle of pyroelectric d
6、etector and defines the quantity of compensation according to the temperature difference between target and its surrounding.The ambient temperature is measured by a digital chip and processed with software.This new way can overcome the defect of thermal resistance.After focused by lens,chopped by ch
7、opper and received by detector, infrared signal is transformed to electric signal whose frequency is 20 Hz in this infrared system.The electric signal is processed,compensated and displayed in micro-controller system after it is amplified,filtered and adjusted by circuit. During design of this infra
8、red system,micro-control is debugged with Wave6000 simulation system and software is compiled in assembly language because of timing relation between every part.The test of this infrared thermometer indicates that precision and stability has improved already.But it couldnt reach our countrys standar
9、ds on medicinal thermometer.AbstractKeywords Infrared thermometer;Pyroelectric detector;Emissivity;Tempera-ture compensation;Micro-controller;Calibration目 录摘要IAbstractII第1章 绪论11.1 引言11.2 红外测温仪的分类 21.2.1 全辐射测温仪21.2.2 单色测温仪31.2.3 比色测温仪41.3 发射率和环境因素对红外测温仪的影响51.3.1 发射率对红外测温仪的影响51.3.2 环境因素对红外测温仪的影响61.4 医
10、用红外测温仪的现状71.5 课题的意义和内容81.5.1 课题的意义81.5.2 课题的内容8第2章 光学系统和光电转换92.1 红外测温仪的光学系统92.1.1 红外测温仪光学系统特点92.1.2 常用红外光学系统结构92.2 红外光学系统设计122.2.1 透镜成像公式132.2.2 透镜成像的误差及对策142.2.3 透镜参数的确定142.3 光电转换152.3.1 红外探测器的种类152.3.2 热释电探测器252.4 本章小结27第3章 电路系统设计283.1 红外信号的调制283.1.1 斩波器的设计283.1.2 斩波器的驱动29 3.2 信号的放大和滤波323.2.1 有源滤波器的设计333.2.2 信号的放大和整形353.3 本章小结37第4章 数据的采集和显示384.1 数据采集384.1.1 A/D转换器的选择384.1.2 ADS7824功能简介384.1.3 单片机与A/D转换器的接口电路414.2 环
