基于弹光调制光谱的多光谱温度测量

Temperature Measurement Using Multi-Spectral Method Based on Photo-Elastic Modulation Spectroscopy

为了实现快速、准确的高温测量,在多光谱辐射理论的基础上,提出一种基于弹光调制光谱的多光谱温度测量方法。对基于弹光调制的多光谱测温装置系统结构进行了详细介绍,并且采用MATLAB软件对温度测量方法进行仿真分析,最后进行实验验证。实验中采用非均匀快速傅里叶变换(NUFFT)算法将高温物体辐射产生的弹光调制傅里叶变换干涉信号进行复原,在对探测器进行光谱响应函数标定的基础上,根据响应函数进行修正得到实际光谱复原图,再利用多光谱温度反演算法得到黑体温度。结果表明,所提方法的温度计算误差为5%左右,并通过标准黑体辐射源进行实验,对温度测量进行了验证。

Objective Temperature is an important parameter in thermodynamics,physics,materials,metallurgy,and other subjects.The development of science and technology and the increased complexity of detection environments have produced greater requirements for the real-time and rapid accuracy of temperature measurement in the fields of high-temperature object temperature measurement and explosion field high-temperature detection.Compared with traditional contact measurement,the non-contact temperature measurement method avoids contact with the material and has advantages in the range and accuracy of high-temperature measurement.Among them,the multi-spectral temperature measurement method finds the true temperature of the target by measuring the radiance of multiple spectra of the target at a certain time.It is fast and non-contact,and produces a high-temperature measurement upper limit.Furthermore,its development has important economic and social significance.The photo-elastic modulation Fourier transform spectrometer has various advantages,such as fast detection speed,wide detectable spectral range,and high resolution.Also,measurement can be achieved in high-speed detection application environments,such as explosion and combustion,and it has a relatively large application range.In this study,we apply the multi-spectral temperature measurement method to the photo-elastic modulation spectrometer and study the target temperature measurement method using the photo-elastic modulation spectrum.Furthermore,we explore the technical approach of multi-spectral temperature measurement suitable for multiple targets and develop a multispectral temperature measurement device to achieve the target temperature.The result of this study is of great significance for temperature measurement on special occasions.Methods In this research,we apply the system structure of a multi-spectral temperature measuring device using a photo-elastic modulation to measure temperature.First,we analyze and explain the principle of multi-spectral temperature measurement.Then,we introduce the system structure of the multi-spectral temperature measurement device based on a photo-elastic modulation.Also,we explain the generation and acquisition methods for photo-elastic modulation interference signals and investigate non-uniform acceleration.Next,the nonuniform fast Fourier transform(NUFFT)algorithm applies the detector to detect a standard light source with known radiation energy and obtain the response curve of the detector.Additionally,MATLAB is used to simulate and analyze the spectrum restoration algorithm and temperature measurement method.Finally,the experiment is verified.In the experiment,the NUFFT algorithm is used to restore the photo-elastic modulation Fourier transform interference signal generated by radiating the high-temperature object.Furthermore,the actual spectral recovery is obtained by correcting the response function figure using the calibration of the spectral response function of the detector,selecting the corresponding measurement wavelength,and applying the multi-spectral temperature inversion algorithm to get the black-body temperature.After 10 repeated experiments at different black-body temperatures,the system temperature measurement is verified.Results and Discussions This study verify the correctness of the multi-spectral temperature measurement algorithm based on photo-elastic modulation spectroscopy using MATLAB simulation analysis(Fig.5,Table 1).A laboratory-built photo-elastic modulation spectrometer is applied for experimental verification,thereby producing the collected black-body interference.Fig.7 shows the reconstructed spectrum after the signal and response correction.This study collects multiple experiments with standard high-temperature black bodies at different temperatures and applies the multi-spectral temperature measurement algorithm to the recovered spectrum.The results show that the measured temperature fluctuates up and down the standard value with a minimum error near 5%of the standard value(Fig.9)and a certain degree of accuracy.Compared with traditional temperature measurement technology,the photo-elastic modulation interference module used in the spectrometer has a faster spectral measurement speed and wide spectral range,and the system has no moving parts and has good stability(Fig.1).Our proposed algorithm can be used in various environments,quickly obtain the radiation field spectrum signal of the high-temperature object,and realize the non-contact measurement of the temperature of the high-temperature object.Conclusions The multi-spectral temperature measurement is a radiation-temperature measurement method with great potential,especially in the absence of information on the emissivity spectrum of the measured object.In this paper,the photo-elastic modulation interference technology is used to collect radiation signals and the accelerated NUFFT algorithm is used to restore the spectrum of the collected interference signals.Accurate temperature measurement is obtained using the multi-spectral temperature measurement method and the standard black body served for verification.Results show that photo-elastic modulation has the advantages of short acquisition time of interference signals,large spectral range,and is a valuable new method.For future work,further in-depth study,which will provide a new method for temperature measurement in special occasions will be considered.