The authors thank Tyler Gorney and Aida Rahim at Luna Innovations for their invaluable technical insight and assistance with our application.
The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory ("Argonne"). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. This work was supported by the U.S. Department of Energy, Office of Nuclear Energy.

1.选择最佳的传感器类型应用<ol><li>请根据采样速度和数据点的数量之间的权衡传感器长度。 注意:一个询问器样品传感器高达50米的长度在2.5赫兹和分辨率&lt;10毫米而其它样品传感器高达10米的长度为5 mm的分辨率和100Hz。 </li><li>选择基于服务温度限制，时间响应，湿度敏感性，和安装配置（裸或毛细管）要求的类型的单模光纤的。 注意:在这里我们使用了直径为155微米的聚酰亚胺涂层单模商业电信光纤。 注意:请参阅表1和2，因为我们已经在我们的实验室中使用的纤维和结构的例子。 </li></ol> 2.试验段安装光纤<ol><li>通过除去长玻璃侧板的一个开口测试部分。 </li><li>钻头直径1毫米的孔在侧壁下盖3毫米线锚（ 图3）。 注:锚认为，支持传感器钢丝。锚间距可以按照试验部分的尺寸和从流预期动态加载而变化。这里使用20mm的节距被证明与在流最小的振动稳定接近1米/秒。振动腐败DTS信号，并与长传感器15,16更多的问题。 </li><li>串穿过试验段的直径127微米的钢丝段通过在罐的两端将其直接连接到一个黄铜锚。重复，直到共有横跨罐串成47线段是。 </li><li>使用通信/电工剪刀储备接续连接器和光纤端接要消耗削减50米光纤（可能&lt;0.5米的而是依靠熟练的拼接）。收集在一个小阀芯这种光纤，在〜直径为50毫米。 </li><li>铺设所述第一传感器段在选定测量温度机智的区域的一个边缘小时传感器阵列。 注:在第一个段被固定在适当的位置后，将纤维将被循环用于与相邻段，固定在适当位置，并且分配用于在反复的过程，建立该阵列，直到所用的所有的纤维的下段更多的纤维。 </li><li>织纤维的上方和相邻电线下面，根据需要从罐的一侧从卷轴工作到其他，分配光纤。 注:纤维垂直于丝为如图3与编织中的另一个方向和流量支撑它克服重力的力。 </li><li>第一个光纤段的每一端连接到传统的透明胶带或聚酰亚胺薄膜胶带盖子。阵列的第一区段现在已经到位。 注意: 不要安装传感器绷紧像吉他弦，而是足以绷紧是直的，并采取了明显的松弛。如果传感器被张紧，在支撑小变形， 例如 ，热EXPAN盖子的锡永，将改变这种紧张和产生异常的信号偏移和测量误差。 </li><li>环路光纤180度，以将其返回给下一个段，如图所示。 4，并将其在10毫米从第一段的距离的磁带在盖。 注:最小化环直径，因为它是"浪费纤维"（不是阵列的一部分），但它应是可容忍的应力大约30毫米或更多。这里使用的纤维已经耐受30毫米直径的环数月，没有明显的信号损失，但限制将与纤维类型而变化。对于此处使用的纤维，制造商指定的"短期的"弯曲半径极限为≥10mm，并且"长期"限制为≥17毫米。 </li><li>再次编织网之间的纤维朝向位置的罐和磁带的相对侧。重复循环，盘带和织造工艺，直到用完所有的光纤。 </li></ol> 3.接头连接和Termina重刑光纤<ol><li>拼接LC型单模连接器连接到使用以下制造商的说明17熔接的光纤的一端。 </li><li>切断与电工/通信剪刀〜0.25米终止纤维并用下列制造商的说明书一熔接拼接到光纤的另一端，一次。 注意:此组件（纤维，连接器，和终止）现在将被称为"传感器"。终止纤维从激光脉冲分散残留信号，以防止其返回到询问器。 </li></ol> 4.传感器配置<ol><li>堵塞传感器插入读写端口的LC型的连接器端和启动配置软件。 </li><li>选择"获取"（从温度数据不同），扫描完成时自动显示生成传感器振幅数据。 注意:具有良好的接头传感器将拥有该基因的痕迹图劳尔埃特性。 5。一个可怜的拼接可以通过在连接器预计模糊的本底噪声或显性反射表示。如果一个贫穷的拼接之嫌，回到步骤3，重复拼接过程。 </li><li>通过拖动显示在屏幕上的传感器的开始和红色光标到结束黄色光标选择传感器的活性部分。 </li><li>给传感器的名称，然后选择"保存文件传感器"。 注:现在配置并准备使用的传感器。 </li><li>关闭组态软件，并切换到测量软件。 </li></ol>试验段中的5 MAP传感器位置<ol><li>开始审讯测量软件和加载刚刚配置的传感器。 </li><li>烙铁连接到设置为〜40％的可变变压器，预热5-10分钟。 注:烙铁映射产生局部温度尖峰。烙铁可一个ELT纤维涂层和破坏传感器，具有低变压器的设置开始，只用足够的力量来获得清晰的尖峰。一个10〜20℃，足以秒杀这个过程。 </li><li>在读写器软件中选择"测量"绘制屏幕上的实时数据。 </li><li>缩小，以显示在屏幕上的整个传感器。 </li><li>容纳邻近传感器烙铁并简要从那里它符合盖子（ 图4）的排气触摸它在第一映射点，此处的段最远。 </li><li>通过软件测试部分中的相应的物理位置沿着指示的温度峰值记录位置。 </li><li>重复5.5-5.6所有49段的结束点映射。 </li></ol> 6.传感器基线:链接到绝对温度<ol><li>位置的一个或多个温度的标准， 例如 ，TC或电阻温度检测器（RTD）时，DTS邻近充当联的DTS读数绝对德标准温度。 </li><li>通过更换在步骤2.1除去长玻璃侧板关闭油箱。 </li><li>通过在毯子或常规隔热板包裹它隔离罐，并允许它放置过夜建立的等温气氛。 </li><li>启动读写器软件，选择"基线"（或"皮重"），并同时注意/录制TC（或RTD）读数。当软件与基线完成后，选择"测量"绘制实时数据来检查基线的质量。 注意:此关键步骤确定DTS的基线和信号现在应指示为零， 即 ，ΔT（x）= 0±度的一小部分。从现在开始，如罐温度从基准温度发散信号会有所不同:ΔT（x）的= T（x）的绝对 - T的基础上 ，其中T（x）的绝对值是沿纤维和T 基的绝对温度为基准温度6,18。如果测试section是非等温，T 基地将位置的函数， 即 T 基 （X），除非T 碱基 （X）与一个以上的TC或RTD（见讨论部分）映射的精度将受到影响。 不要动或触摸传感器，直到第7步完成。以任何方式使劲就可以引入可能会降低测量精度偏移。 </li><li>检查活信号，它不应该从零远漂移。如果漂移过大的应用程序（我们的极限大约是0.5°C〜后5分钟），允许试验段更多的时间来达到热平衡和/或改善绝缘（参见下面的注释），然后重复步骤6.4。 注意:信号质量是总是立即最好基线后，将根据不同的测试部分内的温度分布随时间漂移。基衬之前良好的绝缘性和长期的等待期将减少漂移和测量误差。相当大的，快速的漂移显示测试部分不温，这将最终导致不准确的测量。 </li><li>选择在询问器软件的记录功能和记录的DTS数据的10-100扫描只是用来产生基线相同的停滞，在等温条件。记录还TC / RTD读数。 注:这是可能由从应变测试部分或支柱，流动或意外变形而产生偏移后测检查储备数据。 </li></ol> 7.运行测试<ol><li>接通压缩机产生的空气流，并调整流量控制器以1.25千克/秒给每个信道相匹配的流速。 注:平均入口速度为1.1米/秒和雷诺数为10,000。 </li><li>设置加热器功率为600瓦到暖东喷射20℃的西射流，这是在环境温度以上。 </li><li>让系统运行在一夜之间达到平衡。 </li><li>第二天，检查现场DTS信号来评估的噪音水平。选择传感器"计升ength"的软件来实现可接受的噪声水平（30毫米计此处使用）。 注:量具长度对应于传感器的空间分辨率。在一般情况下，信号噪声随着距长度减小，并且作为流动引发的振动增大（见的用户指南和参考文献13和14）。 </li><li>在4赫兹登录DTS 2000扫描。 </li><li>关闭加热器功率和气流。让坦克坐过夜，以达到平衡并记录10-100 DTS扫描，以补充保存后测预测试数据集偏移检查。 </li></ol> 8.数据分析<ol><li>选择在询问器软件的主窗口中的后处理的功能，并导入试验数据，这是在一个专用的二进制格式。 </li><li>导出的数据为可由常规电子表格程序被读出的纯文本文件。 注:此数据代表沿纤维，其中ΔT（x）= T（x）的ABS测量ΔT - T的基地 。它不包含任何引用在试验部分的位置（参照图6）。更多详细信息，询问用户指南和参考文献6和16这步和下一个可用。 </li><li>导入文本数据转换成传统的电子表格，并加入t 基准 ，通过TC或RTD步骤6.4测量，将所有数据转换为绝对温度。 注:转换到绝对温度是一个简单的单值偏移校正:T（x）的ABSΔT=（X）+ T 基线 ，因为我们已经规定，试验段基线时是等温的。 </li><li>使用电子表格软件或类似的数据处理程序，以分解T（x）的数据，并将其映射到像在图7和8中所示的测试部分内的物理位置。 注意:程序将利用与在步骤5烙铁收集的数据。 </li></ol>

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The authors have nothing to disclose.

我们已经证明，在一个流体动力学实验使用的DTS。这些传感器的主要优点是，可以从一个单一的传感器来获得测量点的大数目。这里使用的DTS产生在4067点的数据跨0.5×0.8 M面，远远超越了传统点传感器的可行的限度，如热电偶。而这样的数据密度可以通过光学技术被超过诸如激光诱导荧光（LIF），一个DTS将在不透明流体和缺乏光学访问的应用程序的功能。一个DTS的高数据密度是适于参与计算流体力学代码验证实验。 基线是确定的测量精度在协议的关键步骤和中央。恒温试验段是必不可少的，以确保整个DTS是在一个温度基线时。如果这是不可能的，T 碱基变为T 碱基 （x）的，这应该是MAPP通过安置在靠近DTS多个气旋编虽然基线质量可以用这种方式加以改进，它映射DTS基线的标准转换为绝对温度的过程复杂化。 总是在寻找基线后菌株来源，可以引入不可预知的信号变化。这些来源为，例如，测试部分的热膨胀，绵延传感器，支架的运动，动态负载从高流速或流动引起的振动。等温条件下的预处理和后测的测量将有助于识别这些问题。 应变灵敏度是本瑞利基于散射的DTS的主要缺点。不像像热电偶常规传感器，它是要处理，湿度和振动的影响。这些问题是最相关这里演示裸传感器的配置，但远不如重要的装在毛细管的传感器。 不同于传统的传感器，一个DTS不能与文书它跟踪到一个公认的校准标准如NIST（美国国家标准技术研究所）采购。 原位校准是必要的，优选的等温试验段，这可能是在某些困难应用程序。振动是在大量试验段串成裸光纤特别关注的。我们已与跨越罐的长轴在为1.7μm段长度一垂直取向的阵列混合成功。 28 m长光纤和16段的结构的一项研究18期间表现良好，但试图把它扩大到53米，29段不成功16。 在一般情况下，信号噪声为任何传感器长度和配置可通过增加在其上读写软件计算瑞利信号移位的测量长度被减小，但是这减少了有效空间分辨率。每个APPLICA化，必须处理好信号中的噪声和空间分辨率之间自身的平衡。同样，这种困难是可以很大程度上是由住房毛细管传感器在温度过高的响应时间为代价避免。 这种相对较新的测温技术的发展需要，以减少振动的敏感性。这项工作大部分将必然涉及读写器的硬件和软件。传感器本身也可以被改进，以减少处理和湿度的变化，这是由光纤涂层的影响的灵敏度。工作可以专注于开发优于聚酰亚胺和丙烯酸酯涂层纤维目前市售涂料。

计算流体动力学（CFD）码被用于模拟各种流体系统，从围绕飞机和汽车的气流向下动脉血液流动。这种模拟的范围和保真度已经渐渐计算能力的可用性。然而，尽管高级仿真的复杂，其精度和可靠性往往难以量化。在实践中，CFD代码的准确性是通过在一个过程被称为代码验证比较与实验数据的模拟评估。 一个典型的实验数据集包括主要的速度和温度的测量，无论是理想的高时空分辨率，方便严格的代码验证。速度场能够以高分辨率使用粒子图像测速（PIV），一个成熟的光学技术1,2映射。相反，它是困难的温度场与媲美PIV的分辨率映射。光学升技术如激光诱导荧光可用3,4-，但它们需要摄像机和相对高功率激光器，和不适合于不透明流体。 另一种方法是在基于瑞利散射和掠波长干涉测量（SWI）5-7分布式温度感测的相对较新的技术提供。数千温度测量可以沿着单个光纤来获得。分布式温度传感器（DTS）可以跨越在不适合基于图像的技术8大环境流场和功能。也有DTSS基于拉曼和布里渊散射9,10，但传感器基于瑞利散射和SWI提供空间和时间分辨率更适合于典型流体动力学实验。 虽然DTSS报价数据密度远远超过传统的传感器，例如热电偶（TCS），传感器根据瑞利scatte环响应应变以及温度11。如果光纤涂层具有吸湿性，传感器还响应湿度变化12,13。水蒸气的吸收溶胀的涂层而解吸收缩它14，该菌株底层玻璃纤维，并改变该信号。其结果，精度由装卸，振动，并在相对湿度的变化的影响。这是完全不同于传统的传感器和必须遵守这样非常规的安装和测量方法来获得准确的数据。本文阐述了在热混合实验中使用了DTS的，提出的协议和准则，以确保准确性。 这里使用的DTS是基于一个光纤波导内检测和瑞利散射的分析。的杂质和结构变化沿着光纤芯的随机分布引起所独有的纤维和通常的稳定反向散射图案。频谱和振幅这个图案可以被理解为作为纤维签名。物理变化如温度变化或应变改变以可重复的方式的签名，并检测签名的变化是使用光纤作为传感器的基础。 图1示出光电传感装置的主要部件，称为光分布传感器询问器，并在这里被表示简称为"询问器"。在称作掠波长干涉测量的技术，低功率可调谐激光器发射的窄带信号进入光纤用于登记所得散射5-7的目的。激光器在几个纳米的间隔扫过并参考和测量腿之间分裂信号。来自传感器的散射光与基准信号以产生在检测器的干扰信号相结合。检测器输出被数字化并分析以检索瑞利散射信号。该Rayle在波长下传感器温度（株，或湿度）变化的传感器位移的IGH签名。这种波长偏移的幅度到传感器的敏感性，这是与纤维类型，其中有一个校准因子类似于一个TC的塞贝克系数相关联的物理常数有关。 图2示出在作为本研究中使用的测试部分的玻璃缸。坦克后面的相机给规模感。空气进入通过两个六边形导管和通过排气口排出之前相混合。为了突出喷气机，一个流流与油雾种子，而其他保持纯净的空气。水箱盖有覆盖着黑色的屏幕聚合物的一个窗口。虽然在照片中不可见时，DTS被暂停下面黑屏。 50米长的DTS被安装在水箱盖的下方，如图所示。 3，它是由直径155微米的聚酰亚胺被覆光纤塑成挂在油箱端板之间串起127微米直径的钢丝。该传感器通过以交替的图案的丝机织物和环来回穿过槽49次。它跨越一个0.5×0.8 M面，当用10mM间距过采样产生4赫兹和1355独立的数据点为30毫米的空间分辨率，4067个数据点。这种高密度的温度数据的补充速度数据，提高数据集进行CFD验证值。该协议概述了传感器选型，制造和配置，而专注于特别关注在一个流体动力学实验使用DTS的过程。

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		<tr height="190">
			<td height="190" style="height:190px;width:139px;">Sensor interrogator</td>
			<td style="width:155px;">Luna Inc.</td>
			<td style="width:147px;">ODiSI-A and -B</td>
			<td style="width:172px;">The two systems differ primarily in speed and spatial resolution</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:139px;">Fusion splicer</td>
			<td style="width:155px;">Fujikura</td>
			<td style="width:147px;">70S</td>
			<td style="width:172px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:139px;">Cleaver</td>
			<td style="width:155px;">Fujikura</td>
			<td style="width:147px;">CT-3A</td>
			<td style="width:172px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:139px;">3-hole jacket stripper</td>
			<td rowspan="2" style="width:155px;">Fiber Instrument Sales</td>
			<td rowspan="2" style="width:147px;">F11301T</td>
			<td rowspan="2" style="width:172px;"></td>
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		<tr height="22">
			<td height="22" style="height:22px;width:139px;">jacket stripper</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:139px;">Optical fibers</td>
			<td style="width:155px;">OFS, Specialty Photonics Division</td>
			<td style="width:147px;">BF06160-02</td>
			<td style="width:172px;">Polyimide coating</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:139px;">Optical fibers</td>
			<td style="width:155px;">Newport Corp.</td>
			<td style="width:147px;">F-SM1500-4.2/50</td>
			<td style="width:172px;">Acrylate coating</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:139px;">Connector</td>
			<td style="width:155px;">AFL Global</td>
			<td style="width:147px;">FUSE-LC-9U-SMA-6</td>
			<td style="width:172px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:139px;">Termination fiber</td>
			<td style="width:155px;">OFS, Specialty Photonics Division</td>
			<td style="width:147px;">552 HPWR 040</td>
			<td style="width:172px;"></td>
		</tr>
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fiber optic distributed sensors for high-resolution temperature field mapping

的计算流体动力学（CFD）码的可靠性是通过与实验数据相比较的模拟检查。一个典型的数据集主要包括速度和温度读数，最好都具有高时空分辨率，方便严格的代码验证。而经由光学测量技术如粒子图像测速被容易地获得高分辨率的速度数据，它已被证明难以用类似的分辨率，得到的温度数据。传统的传感器，如热电偶可以不填这个角色，但是最近根据瑞利散射和后掠波干涉分布式传感的发展提供适合的CFD代码验证工作的分辨率。可以沿着一个单一的薄光纤在数百赫兹的生成数以千计的温度测量的。传感器功能过大的温度范围和不透明的液体，其中光学技术不适合之内。但这种类型的传感器是应变和湿度以及温度敏感，因此精度由装卸，振动，并在相对湿度的变化的影响。这样的行为是完全不同于传统的传感器等非传统的安装和运行程序是必要的，以确保精确的测量。本文阐述了在25和45℃涉及两个喷气热混合实验实施瑞利散射型分布式温度传感器。我们提出的标准来引导光纤的选型传感器，并描述安装设置了喷射搅拌实验。我们举例说明传感器基线，哪个环节读数绝对温度标准，并讨论实际问题，如因流致振动误差。这种材料可以帮助那些有兴趣在具有流体动力学实验和类似应用的高数据密度和带宽的温度测量。我们强调具体到这些传感器considera陷阱化在实验的设计和操作。

原始的DTS数据被绘制在图。 6示出了从基线的温度（大约20℃）与沿传感器的距离测量ΔT。该数据是在这个意义上，它已没有被转换为绝对温度也不映射到试验部分内的物理位置"原始"。数据基于30毫米标距长度，这提供了超过50微米的全部传感器长度1666独立测量。 30毫米计在中，增加数据点的数目，以5000的过采样模式10mm的间隔施加。这样的数据密度不切实可行传统的传感器，如热带气旋。 在图中x = 0。 6，传感器是在坦克的东端，并且随着X增加它循环来回向西结束。峰值出现在传感器经过热喷东部，然后消失它是在寒冷的西部JE吨。情节说明如何即使从单个的DTS的原始信号可以提供温度的基本写照在一个相当宽的区域。注意对纤维，这是由于流致振动的西端信号中的噪声。虽然震动是不可见的肉眼，它足以降低信号，我们有长传感器（&gt; 10米）最经常看到这个问题。 原始数据被映射到在图测试部分。 7，其示出了在由DTS的阵列形成的0.5×0.8 m测定面内温度。的观点是从油箱向下俯瞰盖上面。六边形的通道轮廓包括作为定向援助。轮廓是基于4067个数据点以来的盖子下贴环路被排除在外。相邻的传感器段之间的线性内插用于创建二维轮廓。 钍Ë轮廓提供了盖下方有超过东部喷气温暖区域的热模式的清晰感，但它周围不居中。也很明显，是围绕罐中平面，这是在图上y = 0的一个粗略的对称性。这种类型的温度数据是一个有用的恭维速度数据涉及热混合和传热流体动力学研究。严谨代码验证需要的温度和速度等领域高分辨率数据。 相同的传感器数据可被处理以显示温度波动的幅度。 2,000扫描数据集的RMS（均方根）在图8中绘出。品红标志着在温度波动相对较高的区域。这也是高湍流的区域，其中两个上升射流作为在盖扑来交互。 RMS数据是用于在热混合的上下文湍流模型是有用的。 图1.询问示意图。光学分布式传感器读写器对温度的测量原理组成部分。该系统是基于风靡波长干涉，它刻画了传感器的瑞利散射签名。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54076/54076fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/54076/54076fig2.jpg" /> 图2.测试部分空气喷射搅拌实验:空气通过顶部排气退出之前进入过通过两个六角形管和混合基地坦克。黑屏覆盖盖窗口为3毫米的DTS（不可见）的上方。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54076/54076fig2large.jpg" target="_blank">PL</a>轻松点击此处查看该图的放大版本。 <img alt="图3" src="/files/ftp_upload/54076/54076fig3.jpg" /> 图3.安装DTS配置。储罐显示在贮长轴架设钢支撑线之间编织DTS的俯视图。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54076/54076fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图4" src="/files/ftp_upload/54076/54076fig4.jpg" /> 图4. DTS特写。特写DTS的照片从内部向上盖在罐体突出传感器循环，附件，第一个测试点的位置用烙铁进行映射视图。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54076/54076fig4large.jpg" target="_blank">请点击此处查看大图此网络连接</a>古尔。 <img alt="图5" src="/files/ftp_upload/54076/54076fig5.jpg" /> 图5.瑞利散射信号。记录传感器配置实用程序（此处显示为清楚起见短传感器）典型的瑞利散射信号。正确的终止将产生尖锐的信号下降至本底噪声。轻微信号的步骤和适度反映在连接器是正确的拼接连接器的特点。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54076/54076fig5large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图6" src="/files/ftp_upload/54076/54076fig6.jpg" /> 图6.原始的DTS数据，与热东喷射原料的DTS数据的在45℃下单次扫描和冷西喷射在25℃出现高峰，其中传感器是直接<html>上述热喷。回想一下，传感器环回和罐壁之间来回。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54076/54076fig6large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图7" src="/files/ftp_upload/54076/54076fig7.jpg" /> 图7.测量空气温度低于盖子。DTS槽内转换为绝对温度，并映射到物理位置的原始数据。根据记录，在4赫兹扫描2000数据。数据间距为10 mm，总的4067绘制的数据点。用于传感器段之间的区域填充线性插值。六边形进气口显示的位置。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54076/54076fig7large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 54076fig8.jpg"/&gt; 图8.根意味着测得的温度的平方（RMS）。在图绘制数据的有效值。 7，品红色表示高温度波动和冷热飞机的热混合。六边形进气口显示的位置。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54076/54076fig8large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="表格1" src="/files/ftp_upload/54076/54076table1.jpg" /> 表1阶量值热响应时间对选定的种类的纤维和外壳配置在横流以1米/秒和20℃。 <img alt="表2" src="/files/ftp_upload/54076/54076table2.jpg" /> 表2.近似的工作温度范围和湿度敏感度选定涂层配置。

Watch this Scientific Journal Video about Fiber Optic Distributed Sensors for High-resolution Temperature Field Mapping at JoVE.com

Fiber Optic Distributed Sensors for High-resolution Temperature Field Mapping

我们演示如何使用光纤分布式传感器用于映射混合空气喷射的温度场。瑞利散射基于传感器产生数千个数据点沿单一光纤提供出色的空间分辨率是高不可攀的传统传感器，如热电偶。

对于高分辨率温度场测绘光纤分布式传感器

The reliability of computational fluid dynamics (CFD) codes is checked by comparing simulations with experimental data. A typical data set consists ...

fiber-optic-distributed-sensors-for-high-resolution-temperature-field

Nanyang Technological University

Research

JoVE Journal

Engineering

11.9K 次观看.  Argonne National Laboratory. 我们演示如何使用光纤分布式传感器用于映射混合空气喷射的温度场。瑞利散射基于传感器产生数千个数据点沿单一光纤提供出色的空间分辨率是高不可攀的传统传感器，如热电偶。 

视频: Fiber Optic Distributed Sensors for High-resolution Temperature Field Mapping

Development of Whispering Gallery Mode Polymeric Micro-optical Electric Field Sensors

Optical modes of dielectric micro-cavities have received significant attention in recent years for their potential in a broad range of applications. The optical modes are frequently referred to as "whispering gallery modes" (WGM) or "morphology dependent resonances" (MDR) and exhibit high optical quality factors. Some proposed applications of micro-cavity optical resonators are in spectroscopy1, micro-cavity laser technology2, optical communications3-6 as well as sensor technology. The WGM-based sensor applications include those in biology7, trace gas detection8, and impurity detection in liquids9. Mechanical sensors based on microsphere resonators have also been proposed, including those for force10,11, pressure12, acceleration13 and wall shear stress14. In the present, we demonstrate a WGM-based electric field sensor, which builds on our previous studies15,16. A candidate application of this sensor is in the detection of neuronal action potential.
The electric field sensor is based on polymeric multi-layered dielectric microspheres. The external electric field induces surface and body forces on the spheres (electrostriction effect) leading to elastic deformation. This change in the morphology of the spheres, leads to shifts in the WGM. The electric field-induced WGM shifts are interrogated by exciting the optical modes of the spheres by laser light. Light from a distributed feedback (DFB) laser (nominal wavelength of ~ 1.3 &mu;m) is side-coupled into the microspheres using a tapered section of a single mode optical fiber. The base material of the spheres is polydimethylsiloxane (PDMS). Three microsphere geometries are used: (1) PDMS sphere with a 60:1 volumetric ratio of base-to-curing agent mixture, (2) multi layer sphere with 60:1 PDMS core, in order to increase the dielectric constant of the sphere, a middle layer of 60:1 PDMS that is mixed with varying amounts (2% to 10% by volume) of barium titanate and an outer layer of 60:1 PDMS and (3) solid silica sphere coated with a thin layer of uncured PDMS base. In each type of sensor, laser light from the tapered fiber is coupled into the outermost layer that provides high optical quality factor WGM (Q ~ 106). The microspheres are poled for several hours at electric fields of ~ 1 MV/m to increase their sensitivity to electric field.

A high-sensitivity photonic micro sensor was developed for electric field detection. The sensor exploits the optical modes of a dielectric sphere. Changes in the external electric field perturb the sphere morphology leading to shifts in its optical modes. The electric field strength is measured by monitoring these optical shifts.

回音壁模式聚合物微光学电场传感器的发展

Optical modes of dielectric micro-cavities have received significant attention in recent years for their potential in a broad range of applications. The ...

科研

工程学

High-resolution, High-speed, Three-dimensional Video Imaging with Digital Fringe Projection Techniques

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses triangulation between matching points in two views of the same scene at different angles to compute depth.&#160;However, unlike a stereo-based method, DFP uses a digital video projector to replace one of the cameras1. The projector rapidly projects a known sinusoidal pattern onto the subject, and the surface of the subject distorts these patterns in the camera&#8217;s field of view. Three distorted patterns (fringe images) from the camera can be used to compute the depth using triangulation.
Unlike other 3D measurement methods, DFP techniques lead to systems that tend to be faster, lower in equipment cost, more flexible, and easier to develop.&#160;DFP systems can also achieve the same measurement resolution as the camera.&#160;For this reason, DFP and other digital structured light techniques have recently been the focus of intense research (as summarized in1-5). Taking advantage of DFP, the graphics processing unit, and optimized algorithms, we have developed a system capable of 30&#160;Hz 3D video data acquisition, reconstruction, and display for over 300,000 measurement points per frame6,7.&#160;Binary defocusing DFP methods can achieve even greater speeds8.
Diverse applications can benefit from DFP techniques. Our collaborators have used our systems for facial function analysis9, facial animation10, cardiac mechanics studies11, and fluid surface measurements, but many other potential applications exist.&#160;This video will teach the fundamentals of DFP techniques and illustrate the design and operation of a binary defocusing DFP system.

This video describes the fundamentals of digital fringe projection techniques, which provide dense 3D measurements of dynamically changing surfaces.&#160;It also demonstrates the design and operation of a high-speed binary defocusing system based on these techniques.

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses ...

Construction of a High Resolution Microscope with Conventional and Holographic Optical Trapping Capabilities

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular organelles 2,3, as well as for high spatial and temporal resolution readout of their position relative to the center of the trap. The system described herein has one such "traditional" trap operating at 980 nm. It additionally provides a second optical trapping system that uses a commercially available holographic package to simultaneously create and manipulate complex trapping patterns in the field of view of the microscope 4,5 at a wavelength of 1,064 nm. The combination of the two systems allows for the manipulation of multiple refractive objects at the same time while simultaneously conducting high speed and high resolution measurements of motion and force production at nanometer and piconewton scale.

The system described herein employs a traditional optical trap as well as an independent holographic optical trapping line, capable of creating and manipulating multiple traps. This allows for the creation of complex geometric arrangements of refractive particles while also permitting simultaneous high-speed, high-resolution measurements of the activity of biological enzymes.

高分辨率显微镜与常规和全息光学捕获能力建设

High resolution microscope systems with optical traps allow for precise manipulation of various refractive objects, such as dielectric beads 1 or cellular ...

In-situ Tapering of Chalcogenide Fiber for Mid-infrared Supercontinuum Generation

Supercontinuum generation (SCG) in a tapered chalcogenide fiber is desirable for broadening mid-infrared (or mid-IR, roughly the 2-20 &mu;m wavelength range) frequency combs1, 2 for applications such as molecular fingerprinting, 3 trace gas detection, 4 laser-driven particle acceleration, 5 and x-ray production via high harmonic generation. 6 Achieving efficient SCG in a tapered optical fiber requires precise control of the group velocity dispersion (GVD) and the temporal properties of the optical pulses at the beginning of the fiber, 7 which depend strongly on the geometry of the taper. 8 Due to variations in the tapering setup and procedure for successive SCG experiments-such as fiber length, tapering environment temperature, or power coupled into the fiber, in-situ spectral monitoring of the SCG is necessary to optimize the output spectrum for a single experiment.
	In-situ fiber tapering for SCG consists of coupling the pump source through the fiber to be tapered to a spectral measurement device. The fiber is then tapered while the spectral measurement signal is observed in real-time. When the signal reaches its peak, the tapering is stopped. The in-situ tapering procedure allows for generation of a stable, octave-spanning, mid-IR frequency comb from the sub harmonic of a commercially available near-IR frequency comb. 9 This method lowers cost due to the reduction in time and materials required to fabricate an optimal taper with a waist length of only 2 mm.
	The in-situ tapering technique can be extended to optimizing microstructured optical fiber (MOF) for SCG10 or tuning of the passband of MOFs, 11 optimizing tapered fiber pairs for fused fiber couplers12 and wavelength division multiplexers (WDMs), 13 or modifying dispersion compensation for compression or stretching of optical pulses.14-16

In-situ Tapering of Chalcogenide Fiber for Mid-infrared Supercontinuum Generation

We describe a method for in-situ tapering of As2S3 fibers to achieve efficient mid-infrared supercontinuum generation. By tapering while monitoring the supercontinuum&#x2019;s spectrum, the spectral width can be maximized for a fiber taper. In-situ fiber tapering can be applied to optimize the performance of other fiber-based devices.

原位减量硫系中红外光纤产生超连续谱

Supercontinuum  generation (SCG) in a tapered chalcogenide fiber is desirable for broadening mid-infrared  (or mid-IR, roughly the 2-20 &mu;m wavelength ...

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

对于新材料的低温磁输运测量先进的实验方法

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film ...

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy

High resolution optical spectroscopy methods are demanding in terms of either technology, equipment, complexity, time or a combination of these. Here we demonstrate an optical spectroscopy method that is capable of resolving spectral features beyond that of the spin fine structure and homogeneous linewidth of single quantum dots (QDs) using a standard, easy-to-use spectrometer setup. This method incorporates both laser and photoluminescence spectroscopy, combining the advantage of laser line-width limited resolution with multi-channel photoluminescence detection. Such a scheme allows for considerable improvement of resolution over that of a common single-stage spectrometer. The method uses phonons to assist in the measurement of the photoluminescence of a single quantum dot after resonant excitation of its ground state transition. The phonon&#39;s energy difference allows one to separate and filter out the laser light exciting the quantum dot. An advantageous feature of this method is its straight forward integration into standard spectroscopy setups, which are accessible to most researchers.

The manuscript describes a method of phonon-assisted quasi-resonant fluorescence spectroscopy that incorporates both laser-limited resolution and photoluminescence (PL) spectroscopy. This method utilizes optical phonons to provide linewidth-limited resolution spectra of atom-like semiconductor structures in the energy domain. The method is also easily realized with a single spectrometer optical spectroscopy setup.

高分辨率声子辅助准共振荧光光谱仪

High resolution optical spectroscopy methods are demanding in terms of either technology, equipment, complexity, time or a combination of these. Here we ...

High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings

Micro-electronic devices often undergo significant self-heating when biased to their typical operating conditions. This paper describes a convenient optical micro-imaging technique which can be used to map and quantify such behavior. Europium thenoyltrifluoroacetonate (EuTFC) has a 612 nm luminescence line whose activation efficiency drops strongly with increasing temperature, due to T-dependent interactions between the Eu3+ ion and the organic chelating compound. This material may be readily coated on to a sample surface by thermal sublimation in vacuum. When the coating is excited with ultraviolet light (337 nm) an optical micro-image of the 612 nm luminescent response can be converted directly into a map of the sample surface temperature. This technique offers spatial resolution limited only by the microscope optics (about 1 micron) and time resolution limited by the speed of the camera employed. It offers the additional advantages of only requiring comparatively simple and non-specialized equipment, and giving a quantitative probe of sample temperature.

Europium thenoyltrifluoroacetonate (EuTFC) has an optical luminescence line at 612 nm, whose activation efficiency decreases strongly with temperature. If a sample coated with a thin film of this material is micro-imaged, the 612 nm luminescent response intensity may be converted into a direct map of sample surface temperature.

高分辨率热显微成像采用铕螯合物的荧光涂料

Micro-electronic devices often undergo significant self-heating when biased to their typical operating conditions. This paper describes a convenient ...

Nanostructured Ag-zeolite Composites as Luminescence-based Humidity Sensors

Small silver clusters confined inside zeolite matrices have recently emerged as a novel type of highly luminescent materials. Their emission has high external quantum efficiencies (EQE) and spans the whole visible spectrum. It has been recently reported that the UV excited luminescence of partially Li-exchanged sodium Linde type A zeolites [LTA(Na)] containing luminescent silver clusters can be controlled by adjusting the water content of the zeolite. These samples showed a dynamic change in their emission color from blue to green and yellow upon an increase of the hydration level of the zeolite, showing the great potential that these materials can have as luminescence-based humidity sensors at the macro and micro scale. Here, we describe the detailed procedure to fabricate a humidity sensor prototype using silver-exchanged zeolite composites. The sensor is produced by suspending the luminescent Ag-zeolites in an aqueous solution of polyethylenimine (PEI) to subsequently deposit a film of the material onto a quartz plate. The coated plate is subjected to several hydration/dehydration cycles to show the functionality of the sensing film.

A protocol for the synthesis of moisture-responsive luminescent Ag-zeolite composites is described in this report.

纳米银沸石复合材料作为基于发光的湿度传感器

Small silver clusters confined inside zeolite matrices have recently emerged as a novel type of highly luminescent materials. Their emission has high ...

Method for Recording Broadband High Resolution Emission Spectra of Laboratory Lightning Arcs

Lightning is one of the most common and destructive forces in nature and has long been studied using spectroscopic techniques, first with traditional camera film methods and then digital camera technology, from which several important characteristics have been derived. However, such work has always been limited due to the inherently random and non-repeatable nature of natural lightning events in the field. Recent developments in lightning test facilities now allow the reproducible generation of lightning arcs within controlled laboratory environments, providing a test bed for the development of new sensors and diagnostic techniques to understand lightning mechanisms better. One such technique is a spectroscopic system using digital camera technology capable of identifying the chemical elements with which the lightning arc interacts, with these data then being used to derive further characteristics. In this paper, the spectroscopic system is used to obtain the emission spectrum from a 100 kA peak, 100 &#181;s duration lightning arc generated across a pair of hemispherical tungsten electrodes separated by a small air gap. To maintain a spectral resolution of less than 1 nm, several individual spectra were recorded across discrete wavelength ranges, averaged, stitched, and corrected to produce a final composite spectrum in the 450 nm (blue light) to 890 nm (near infrared light) range. Characteristic peaks within the data were then compared to an established publicly available database to identify the chemical element interactions. This method is readily applicable to a variety of other light emitting events, such as fast electrical discharges, partial discharges, and sparking in electrical equipment, apparatus, and systems.

Emission spectroscopy techniques have traditionally been used to analyze inherently random lightning arcs occurring in nature. In this paper, a method developed to obtain the emission spectroscopy from reproducible lightning arcs generated within a laboratory environment is described.

记录实验室闪电弧宽带高分辨率发射光谱的方法

Lightning is one of the most common and destructive forces in nature and has long been studied using spectroscopic techniques, first with traditional ...

Installation Method to Enhance Quality Control for Fiber Reinforced Polymer Spike Anchors

Fiber reinforced polymer (FRP) anchors are a promising way to enhance the performance of externally-bonded FRPs applied to existing structures, as they can delay or even prevent debonding failure. However, a major concern faced by designers is the premature failure of the anchors due to stress concentration. Poor installation quality and preparation of the clearance holes can result in stress concentration that provokes this premature failure. This paper deals with an installation method that aims to reduce the impact of the stress concentration and to provide a proper quality control of the preparation of the drill hole. The method involves three parts: the drilling and cleaning of the holes, the smoothing of the hole edges with a customized drill bit, and the installation of the anchor itself, including the impregnation of the anchor dowel and its insertion. Anchor fans (the free length of the spikes) are then bonded to the external FRP reinforcement. For the end anchorage, and in the case of reinforcements with multiple plies, it is recommended that the anchor fan be inserted between two plies to assist the stress-transfer mechanism. 
The proposed procedure is complemented with a design approach for spike anchors, based on an extensive database. It is proposed that the design follow a number of steps, namely: selection of the anchor diameter and subsequent tensile strength of the connector (that is to say, the anchor before fanning out the free end), evaluation of the reduction in the tensile strength due to bending, provision of enough embedment to prevent slippage failure, and consideration of the number and spacing of anchors for a given reinforcement. In this sense, it should be noted that further research is needed in order to obtain a general expression for the contribution of spike anchors to overall bond strength of FRP reinforcements.

This manuscript presents a method for controlling the quality of installation for spike anchors designed to delay delamination of externally bonded fiber reinforced polymers. The protocol includes the preparation of the drill hole and the insertion process. The most influential parameters on the efficiency of the anchors are discussed.

提高纤维增强聚合物穗锚质量控制的安装方法

Fiber reinforced polymer (FRP) anchors are a promising way to enhance the performance of externally-bonded FRPs applied to existing structures, as they ...