一种高精度黑体辐射源温度测控系统设计

黑体辐射源作为通用红外目标,主要用于红外热成像系统的性能测试、校准和标定,其温度精度和稳定性直接影响产品的最终性能.为实现黑体辐射面温度的高精度测量与控制,提升红外热成像系统整体性能,提出了基于ATmega128单片机的黑体辐射源温度测控系统方案设计;利用MAX1402芯片和PT100完成温度的高精度测量;采用四线制恒压源驱动电路,简化硬件电路设计;基于μC/OS-Ⅱ操作系统平台和PID控制算法完成系统软件设计.详细阐述了MAX1402的校准和PT100标定过程,分析了影响温度测量和控制精度的影响因素并提出了解决方法.实验结果表明,该系统的温度测量绝对误差小于0.01℃,控制稳态绝对误差小于0.004℃.满足红外热成像系统性能提升的需求.

Design of a Temperature Measurement and Control System for Blackbody Radiation Source with High Accuracy

As a universal infrared target,the blackbody radiation source is mainly used for performance testing,calibration and calibration of infrared thermal imaging system,the temperature accuracy and stability directly affect the final performance of product.In order to achieve the high precision measurement and control for the temperature of blackbody radiating surface and enhance the overall performance of the infrared thermal imaging system,a temperature measurement and control system for blackbody radiation source is presented.The high accuracy measurement of the temperature is completed based on MAX1402 and PT100 sensor.Four-wire constant voltage source drive circuit is used to simplify the design of hardware circuit.The system software is designed based on μC/OS-Ⅱ operating system and PID control algorithm.The calibration of MAX1402 and the calibration of PT100 are introduced in detail.Influencing factors that affect the accuracy of temperature measurement and control are analyzed,and the solution is proposed.The experimental results show that the absolute error of temperature measurement is less than 0.01 ℃,and the absolute error of steady-state is less than 0.004 ℃,which meets the requrement of performance enhancement of infrared thermal imaging system.