一种多光谱高温计无源温区的标定方法研究

目前,高温测量中,多光谱高温计具有高分辨率与高信噪比的优点,但无源温区(大于3 000℃)标定方法的发展却远滞后于多光谱高温计制造水平,并已严重影响高温计的测量精度和应用范围。为突破高温测量领域中无源温区标定方法的瓶颈,文章提出了一种多光谱高温计无源温区的标定方法。此方法利用已知温度点的多光谱高温计的输出电压U建立了一种基于幂函数的温度-电压(T-U)模型。在此基础上应用导数最小二乘法对模型参数求解,实现对无源温区的标定。理论和实测数据都验证了此方法的有效性与精度。在多光谱高温测量应用的光谱范围(0.4～1.1μm)内,对精度优于3‰,1%和3%的无源温区标定范围做出理论上的划分。     

用于固体火箭羽焰真温测量的宽量程多光谱高温计

现有的多光谱高温计的测量下限均大于1 173 K(900 ℃),不适用于新型火箭羽焰真温测量范围的要求(900~2 700 K)。为了解决现有的多光谱高温计无法测量1 173 K以下羽焰真温的问题,研制了用于固体火箭发动机羽焰真温测量的宽量程多光谱高温计。该多光谱高温计采用了并联光电探测器阵列相邻像元的方法,并且创建了基于对数函数的900~1 173 K温区的温度标定方法,从而拓宽了高温计的温度测量范围。针对某型号固体火箭发动机羽焰的三个目标点进行了现场测量,实验结果验证了该高温计的有效性。     

用于真空弧等离子体放电阴极温度场测量的多光谱高温计

阴极表面温度是真空弧等离子体放电过程中一个重要参数,对真空弧等离子体的形成、电极腐蚀预测、热传导以及离子源的寿命都有重要影响。真空弧离子源的阴极具有目标小,放电过程快等特点,其温度的测量,对于时间分辨率和空间分辨率要求都很高,阴极表面温度的测量技术的欠缺,使得仅靠理论解析获得的结果难以得到验证。并且等离子体放电过程中测量仪器极易受到弧光的影响,如何避免放电过程中等离子体的辐射也是采用辐射法测量阴极表面温度要考虑的问题。这无疑给其温度场的测试研究带来困难。针对脉冲真空弧等离子体开展阴极表面温度测试实验有着重要意义,在分析了真空弧等离子体放电特性以及背景辐射特性和等离子体放电阴极测温的实际需求,本文基于高速CCD相机研制了一种新型的多光谱高温计。该高温计采用单色高速CCD相机,主要避免RGB彩色相机不能完全滤除背景辐射的弧光。为使用单色CCD相机实现多光谱辐射测温,设计了高温计的光学系统,该系统采用4孔径分光系统。将4种不同波长的滤光片嵌入到1个滤光片中。该研究设计的高温计可用于2 000~6 000 K的等离子体温度测量。并在中国工程物理研究院电子工程研究所进行现场测试,测试过程中将研制的高温计,通过外部触发形式对等离子体放电过程进行跟踪拍摄,高温计完全拍摄到等离子体放电过程。利用真空弧等离子体金属电极阴极放电的实测数据对高温计进行了验证。实验结果表明,设计的新型多光谱高温计能够用于测量真空弧等离子体放电时阴极温度场信息,测量的温度值低于放电电极的沸点温度,与等离子体放电过程中出现气化现象相符,说明高温计测的是等离子体放电阴极的温度。     

多光谱高温计有效波长标定方法研究

针对光纤式多光谱高温计波长标定中由于光纤耦合导致信号太弱而无法获得有效波长的问题,基于普朗克定律,充分结合不同标定温度点的标定值的比值,提出了一种由温度标定数据来确定有效波长的方法。相比于传统的有效波长标定方法,新方法避免了耗时复杂的波长标定过程可以快速获取有效波长。分别采用仿真和实验两种手段来验证新方法的可行性和有效性。仿真结果表明所提出的新方法可行并且具有一定的抗随机误差能力,所得有效波长计算的真温值与实际值的相对误差小于0.7%。实验结果表明提出的新方法能够得到各个通道的有效波长值,进一步验证了该方法的有效性。所提出的新方法也可应用于其他多光谱高温计,为多光谱高温计的研制和应用提供了理论基础。     

可同时测量真温及光谱发射率的8波长高温计

基于提出的新的多光谱测温法的数据处理方法 ,研制了一种可以自动识别目标真温及光谱发射率的新型多波长高温计。其光路系统采用棱镜分光技术 ,克服了以往用光导纤维分光、干涉滤光片限定工作波长的缺点 ;数据采集系统采用 SA6 8D2 2模块 ,可以实现数据的无线传输。基于提出的新的发射率假设模型 ,使得此多波长高温计可用于大多数工程材料的目标真温及光谱发射率的测量     

Measuring the Temperature of Substances upon Fast Heating with a Current Pulse

Features of measuring the temperature of conducting materials (metals, carbide, graphite) with a brightness pyrometer upon heating with a microsecond pulse of electric current are considered. Problems of pyrometer calibration and developing a blackbody model for measuring true temperatures in solid and liquid phases are examined. Estimates of temperature field nonuniformity over a sample and errors of temperature measurement are given.     

Noncontact thermal pyrometry for condensed materials

Pyrometry technique is suggested aimed at minimizing the measurement error and increasing the accuracy of contactless temperature measurements. Significantly, the suggested method of pyrometer calibration allows using a two-tiered approach with preliminary or additional recording of the system’s state and thermal radiation to refine temperature measurements. To improve the reliability of results and extend the application range of thermal pyrometry, it is necessary to decrease the influence of the relative error of the spectral ratio on measuring data.     

超高速碰撞LY12铝靶产生闪光的辐射演化特征

为研究超高速碰撞产生闪光的辐射演化特征,利用建立的瞬态光纤高温计测量系统结合二级轻气炮加载系统,进行了4种实验条件下的超高速碰撞实验。每组实验使用一组光纤探头,基于实验所获原始数据结合标定,通过Matlab编程处理得到了给定实验条件及光纤探头安装方案条件下的闪光强度演化,利用比率法得到碰撞闪光的辐射温度演化特征。实验结果表明,在488~667 nm波长范围内超高速碰撞LY12铝靶产生的闪光强度与辐射温度峰值随碰撞角度（与靶板平面的夹角）的增大而减小。     

数字式激光平面干涉仪校准规范介绍

数字式激光平面干涉仪是用于测量光学元件面形和无焦光学系统波像差的光学仪器。为了统一数字式激光平面干涉仪测量量值，保证其测量结果的准确性和溯源性，编写数字式激光平面干涉仪校准规范。简要介绍了数字式激光平面干涉仪校准规范的构成，被校仪器的技术指标和校准方法等。     

The application analyses for primary spectrum pyrometer

In the applications of primary spectrum pyrometry, based on the dynamic range and the minimum sensibility of the sensor, the application issues, such as the measurement range and the measurement partition, were investigated through theoretical analyses. For a developed primary spectrum pyrometer, the theoretical predictions of measurement range and the distributions of measurement partition were presented through numerical simulations. And the measurement experiments of high-temperature blackbody and standard temperature lamp were processed to further verify the above theoretical analyses and numerical results. Therefore the research in the paper provides the helpful supports for the applications of primary spectrum pyrometer and other radiation pyrometers.     

测量爆炸火焰真温的多光谱温度计的研制——现场实验与测量精度分析

研制了可用于大型爆炸现场的、 测量爆炸火焰真温的多光谱温度计(量程为800~3 500 ℃,波长范围为0.6~1.1 μm)。测量原理进一步改进,加入亮温逼近法解决了二次测量法初值选取困难的问题,并应用此高温计在空旷场地对3 kg TNT炸药爆炸的全过程进行测量。通过实验结果的分析可知,此高温计可以测量爆炸火焰真温变化全过程,对波阵面瞬时温度与燃烧火球温度的测量均具有很好的效果。同时,分析了影响此高温计测量精度的各个因素,得出目前制约多光谱高温计测量精度提高的主要因素仍然为真温算法及标定方法的误差,这为今后研制高精度高温计明确了方向。     

Pyrometer unit for GaAs substrate temperature control in an MBE system

An optical pyrometer designed for precision measurement of the GaAs substrate temperature during MBE growth is considered. The pyrometer can be calibrated against a certain characteristic absolute temperature that is visually determined from a change in the RHEED pattern. This enables one to calculate the absolute temperature of the substrate with regard to its radiant emissivity and minimize the inaccuracy of radiation temperature measurement. The inaccuracy is associated with the deposition of growth products on the pyrometer window.     

Determination of Interior Surface Temperature Using Luminance Measurement of Thermochromic Liquid Crystals

This paper presents a new method to measure interior surface temperature distributions. An image-resolved luminance measurement camera is used to capture light transmitted through thermochromic liquid crystals (TLC). These crystals change their optical properties with temperature. The experiments clearly show a unique relationship between temperature and the luminance value of the TLC. A calibration function is detected to transform the measured luminance distribution into corresponding temperatures. The developed method is applied to a model of an automotive headlamp. The data are compared with results obtained by using standard techniques such as infrared camera and thermocouple measurement. By that, a reasonable accuracy of the developed method of about ± 0.7°C can be determined. Knowing the temperature on both inner and outer surfaces, the heat transfer can be evaluated.     

激光加载下铝材料的冲击温度测量

利用神光Ⅱ装置上搭建的用于激光冲击波实验的温度诊断系统（该系统包括高时空分辨的扫描高温计和谱时分辨的扫描高温计）,以强激光加载铝材料冲击温度的测量,获得了铝材料冲击高温辐射发光谱的高时空分辨信号图像,结合灰体辐射理论模型,计算得到了冲击波速度19.06 km/s时铝材料的冲击温度达2.95 eV,该温度与SESAME库中冲击温度接近。研究结果表明采用该测温系统能够有效诊断金属材料的冲击温度,为后续进一步获取金属材料冲击温度数据奠定了基础。     

光谱辐射照度量值复现中计算大口径固定点黑体拐点温度的新方法

我国光谱辐射照度基准量值复现的理论基础是普朗克定律,它揭示了波长、温度和光谱辐射照度之间存在着精确的定量关系。采用比较法、通过卤钨灯来进行光谱辐射照度量值的保存与传递。其中,黑体的温度测量在量值复现中是最主要的不确定来源。以往都是采用变温黑体作为量值复现的辐射源,其温度通过高温计溯源至温标固定点黑体。为满足我国对地观测、气象遥感、应对气候变化、海洋水色等领域对光谱辐射照度高精度的测量需求,中国计量科学研究院NIM建立了一套14 mm大口径钨碳-碳WC-C高温固定点黑体系统,作为基准辐射源直接复现光谱辐射照度量值,进一步缩短了量值溯源链,减少了温度测量误差。实验中高温计用来测量黑体的相对温度,采用固定点熔化温坪曲线的拐点POI值校准后得到温度绝对值。因此拐点POI的合理评估计算就十分重要。与小口径WC-C固定点黑体不同,大口径固定点的熔化温坪曲线的持续时间更长,但温度起伏也更大,因此广泛用于小口径固定点的传统拐点POI算法不再适用。提出了一种可筛选多次拟合法,用于计算大口径固定点黑体的拐点温度。采用3 mm小口径WC-C和Re-C固定点对新方法的有效性进行验证,结果表明新方法与三种传统方法的平均值的最大偏差为-0.007和-0.001 K,在500 nm引入的光谱辐射照度测量误差分别为0.002 2%和0.000 3%。进一步采用14 mm大口径WC-C大口径固定点对新方法的稳健性进行验证。分析比较了筛选条件、数据平滑处理、拟合范围对拐点POI计算结果的影响,新方法和三种传统POI计算方法的最大影响量分别为0.001和0.633 K,在500 nm引入的光谱辐射照度不确定度分别为0.000 3%和0.20%。所提出的新方法能够有效减小外界因素引入的温度误差,进一步提升光谱辐射照度量值的复现准确度,更适用于大口径高温固定点黑体拐点温度的计算。     

光谱辐照度测量的数学模型及其方法研究

光谱辐照度是光谱辐射计量中最基本的参数，是研究各种辐射源及光电探测器特性的重要依据。为提高光谱辐照度的测量精度和量值溯源等问题，国防科工委光学计量一级站采用BB3200K高温黑体作为基准的辐射源，以新型辐射测温法为基础，通过一系列光辐射理论和几何原理推导出辐射温度与辐射光功率之间的关系；通过对光辐射功率的绝对测量，并结合低温辐射计，从而完成了光谱辐照度量值的精度测量。该理论奠基了以探测器为基础的新的光辐射量传体系。主要介绍了在光谱辐照度标准装置的项目中复现光谱辐照度所建立的数学模型及新的测试方法，给出了测量结果，并简要介绍了基于该理论的测量装置的组成及原理。     

高灵敏度瞬态辐射高温计

 新研制了一台瞬态辐射高温计。它在设计上做了以下改进，采用：（1）双向色性分光镜作为分光器件，将各个通道波长的分光率提高到85%以上；（2）低输入阻抗宽频高增益（50 dB）信号放大技术做为高温计的后续电路，大大提高了高温计的探测灵敏度，同时也保证了测量系统的快速响应；（3）光谱辐照度方法做零前标定，使零前标定工作方便和可靠。以氯化钠单晶作为实例，测量了它在36.0~60.0 GPa冲击压力下的热辐射历史，获得了1 500~3 600 K冲击温度范围内的瞬态光谱辐射，高温计的响应时间优于5 ns。     

Stagnation point transient heat flux measurement analysis from coaxial thermocouples

The transient heat flux measurement at stagnation point is a significant solicitation at highly compressed flow field environment. In aerodynamics surface heating point of view, the estimation of stagnation heat fluxes at the tip of a blunt body is very imperative. When the blunt body is exposed to high-speed flow field environments, at the stagnation point heat transfer would be maximum. The coaxial surface junction thermocouples (CSJTs) are convenient for short duration time scale due to the fast response in the range of millisecond or less (?0.1 ms). These robust CSJTs have the tractability of intensifying them directly on any type of surface and can be used for routine measurement in ground-based impulse amenities as a temperature measuring devices where rapid heat loads are anticipated. In this work, three different types of coaxial thermocouples K-type, E-type, and J-type have been designed and contrived. The microstructural analysis of measuring surface property has been carried out to see the surface morphology using field emission scanning electron microscopy (FESME) and chemical characterization of these CSJTs materials using energy dispersive X-ray analysis (EDXA) technique is used to verify qualitatively appraise the CSJTs materials composition. The thermal coefficient of resistance (TCR) and sensitivity (S) of each coaxial thermocouple have been determined by using oil-bath calibration technique with the linear variation of resistance corresponding to the variation of temperature and found that these coaxial thermocouples are highly sensitive and suitable for highly transient heat transfer measurements. For this purpose, these three types of CSJTs have been tested under highly compressed heated air 310 K temperature for 100 ms at pressure 6.1 bar with Mach number unity (M = 1) using compressor test rig. Numerical simulation has also been carried out with these three RTDs to satisfy the experimental parameters using Ansys Fluent 15.0 and typical transient temperature recorded. Surface heat fluxes recovered from experimental and numerical transient temperatures histories using semi-infinite heat conduction modeling having good agreement with accuracy ±3% or less. This study divulges the expertise of these handmade coaxial thermocouples for transient surface heat flux measurement for short durations at highly compressed air facilities.     

20 kV高压脉冲幅度校准装置设计

针对高压脉冲幅度的量值传递需求,开展了脉冲幅度1～20 kV、脉宽1～100μs的高压脉冲幅度校准装置设计。校准装置以高压MOSFET器件为核心,搭建多级Marx结构实现高压脉冲成型,同时通过截尾回路的设计缩短脉冲下降时间,实现矩形脉冲波形的输出。在Marx结构基础上开展装置整体设计,通过触发脉冲信号及高压直流电源电压调节脉宽与幅度,通过隔离电源及光信号保证了高压隔离强度。装置采用高准确度高压探头和数据采集卡构成校准装置的内部测试系统,其测量值作为校准装置的标准量值,经评定装置脉冲幅度不确定度为2%,并通过两台比对法进行了验证。采用其他多型高压探头对校准装置进行实验测试,结果表明与低压脉冲校准源测试相比,高压脉冲可明显有效地表征高压探头的性能及测量准确度,同时本装置也可作为高压脉冲发生器应用于脉冲功率领域其他用途。     

红外光学系统焦距测量装置校准规范说明

红外光学系统焦距测量装置是红外光学系统焦距校准和检测的技术手段之一。红外光学系统焦距测量装置校准规范不仅应用于计量部门，保证计量部门日常校准工作的准确性、一致性和可溯源性，同时为红外光学系统焦距测量装置生产部门提供了技术依据，满足红外光学系统焦距测量装置用户在申请各种认证过程中对红外光学系统焦距测量系统的要求。简要介绍红外光学系统焦距测量装置校准规范的主要构成和主要参数校准方法及不确定度评定。