笔者对此表示感谢NIST的中子成像仪器设施科学家丹尼尔·赫西医生的帮助，以协助我们中子射线照相。

为Spring传输机制1.自购非定制部件<ol><li>促使弹簧，螺纹杆，螺柱，螺母和垫圈。这些项目中列出了具体的材料/设备的清单。制造球座前购买的弹簧和支架。使用18-8不锈钢（除303），优选为316不锈钢，对所有材料。 </li><li>促使转子。转子是一个球轴承4.5毫米在制成440C不锈钢或E52100合金钢直径。 </li><li>在采购特定材料/设备的列表中列出的直角阀。 </li></ol> 2.自购材料的集装箱<ol><li>促使集装箱。使用旋转模制，聚乙烯硬外壳与保护凹部，因为这些都是已成功测试例的类型。在特定材料/设备清单的情况下满足最低车内空间的要求。 </li><li> PROC茜的泡沫包装。 <ol><li>促使2＃（32公斤/米3）的聚氨酯（酯）泡沫材料。购买足够酯泡沫填充运输集装箱的顶部和底部。购买一块5厘米鸡蛋纸箱酯泡沫。 </li><li>促使2＃聚乙烯（PE）泡沫为7.6厘米厚，并具有足够大的面积以覆盖运输集装箱的宽度和深度。 </li></ol></li></ol> 3.采购和订制配件的制造为Spring的传输机制注意:在本节中描述的定制部件的实施例附图在图2-4中给出。 <ol><li>生产并提交图纸定制供应商或内部车间制造纺纱转子计（SRG）顶针/法兰。关键尺寸如图2给出。自定义制造商必须熟悉超高真空（UHV）的制造技术。顶针是制造相对简单的第二是在许多真空器件公司的能力良好。 </li><li>获得持有SRG的头到凸缘尖齿（参见图1）。这些可以从自带的SRG电子控制单元的商业SRG顶针/法兰装置中取出。每个齿代替由单个螺栓（通常为六角凹头）带有一个锁紧垫圈保持，并且可以通过使用适当的扳手unbolting被移除（例如六角键）。 <ol><li>可替代地，由同一个供应商提供的顶针/凸缘如在先前步骤中制造这些，但超高真空的制造技术不必遵循。使商业SRG齿的精确副本。 </li></ol></li><li>生产和简单的适配器连接到M6螺柱上直角阀连接到8-32全螺纹螺柱（美国标准硬件）提交图纸。参见图3。 </li><li>生产和球架的制造图纸提交。 Critica升尺寸如图4中给出。制造316L不锈钢的滚珠支架按照特高压的制造技术。钉焊接球保持器到一个弹簧的一端。钉焊接弹簧支座的另一端。清洗所有部件按照在第5节给出的清洁过程。 </li><li>切8-32全螺纹螺柱为18毫米的长度和光洁如在第5节。 </li></ol> 4.制作自定义泡沫切出的<ol><li>使切出为在PE泡沫弹簧传输机制。尽可能地追随阀组件的轮廓。用锋利的美工刀手做到这一点;此外，轮廓可以通过专业的包装供应商削减。 </li><li>使用由阀门制造商，并在图2中给出的顶针/法兰尺寸给定的阀门的尺寸。切空间足够顶针大以容纳叉（1.5厘米×3.8厘米）。</li></ol> 5.清洁真空元件的<ol><li>在装配前的清洁超高真空（UHV）所有真空元件。我们推荐的清洁步骤如下。 <ol><li>处理使用丁腈橡胶，乳胶或乙烯基手套真空部件。不要用手直接触摸。 </li><li>使用温和的清洁剂清洗零件（比如在材料/设备列表中列出）溶于蒸馏水或去离子水和无绒布。 </li><li>在溶解于蒸馏水或去离子水，并装在一个超声波清洁器20分钟温和洗涤剂浴地方份。 </li><li>冲洗部分用蒸馏水或去离子水彻底。 </li><li>封面用丙酮和地方部件20分钟的超声波清洗剂。 </li><li>从丙酮中取出部分。封面用乙醇和地点部件20分钟的超声波清洗剂。 </li><li>从乙醇中删除的部分。用蒸馏水或去离子水彻底冲洗。 </li><li>吹零件干后用干燥氮气或清洁干燥空气。 </li><li>让部分空气干燥，在洁净室质量的无绒布24小时。 </li></ol></li></ol> 6.组装弹簧传输机制<ol><li>在组装过程中，穿腈，乙烯基或乳胶手套。请勿触摸真空部分用裸手。 </li><li>收集必要的工具:尖嘴钳，套筒头驱动程序8-32螺母，扳手适配器，尺子或卡钳。用干净的乙醇标尺/微米;清洁使用在第5步程序中所有其他工具。 </li><li>收集所需的部分:阀，顶针，滚珠轴承，滚珠保持器/弹簧组件（参见步骤3.5），18毫米长8-32螺柱，螺纹接头，螺母和锁定垫圈，3-毫米六角扳手和掩蔽胶带。参见图5。 </li><li> Spring的运输机构组件: <ol><li>通过直至其停止顺时针旋转完全关闭直角阀。 </li><li>翻翻阀口，确定M6螺栓centereD于阀座。 </li><li>紧贴螺丝固定适配器到M6螺栓。插入一个特高压清洁扳手或钳子通过端口来获取适配器的贴身越好。 </li><li>插入8-32螺柱到适配器的另一端。紧，因为紧贴越好。 8-32螺柱将通过适配器扩展和推动对M6螺栓。 </li><li>将锁紧垫圈的螺栓8-32，然后螺母。拧紧用干净的插座驱动程序或钳子螺母。该阀可以在这个步骤中被关闭，使紧固更加容易。 </li><li>放置在8-32螺栓螺母。打开它，直到几乎触及另一端的螺母。将锁紧垫圈的螺栓8-32。 </li><li>连接弹簧/球座的8-32螺柱的僵局。打开僵局直到接触锁垫圈。 注:以下步骤介绍了如何检查弹簧组件的长度调整， 见图6。 </li><li>放置转子在定制顶针和用磁体将其固定（从交流ommercial SRG）通过将其上的顶针端，并与胶带固定。转子现在处于顶针的末尾。 </li><li>滑动顶针过春/球架，当球持有者触球停止。测量阀凸缘和顶针凸缘之间的间隙， 如图6。 <ol><li>如果该间隙是在2至6mm的范围内，则跳至步骤6.4.10.2）。 3毫米标称间​​隙是理想的，但在范围内的间隙为2至6毫米就足够了。小于2mm的间隙是不能接受的。 </li><li>删除顶针/法兰装配，待用。如果该间隙是小于2毫米，逆时针旋转支座，使该间隙变大。如果该间隙是大于6毫米，支座顺时针使间隙较小旋转。回到步骤6.4.10。 </li></ol></li><li>删除顶针/法兰装配，待用。如果该间隙是小于2毫米，逆时针旋转支座，使该间隙变大。如果差距大于6毫米，旋转ST顺时针andoff使间隙变小。回到步骤6.4.10。 </li><li>拧紧对抗对峙螺母。 </li><li>通过逆时针旋转打开阀门。 </li></ol></li><li>组装法兰: <ol><li>通过去除胶带和磁铁，小心地让转子推出顶针取出转子。 </li><li>附加使用通过自定义凸缘/顶针的背面侧插入的锁定垫圈与螺栓两个尖齿的凸缘。锁垫圈和螺栓由商业SRG提供。锁垫圈和螺栓并不需要清洁的超高真空。 </li><li>旋转尖齿，使它们彼此平方，如在图1和图9。 </li><li>通过在顶针​​打滑SRG头检查直线齿。头部应该自由滑动的。 </li><li>给两个螺栓最后收紧和对齐的步骤6.5.3重新检查。 </li><li>放置转子放回顶针，一个d用磁铁和胶带固定。 </li></ol></li><li>完成春季大会运输: <ol><li>放置铜或镀银铜垫圈阀口上。 </li><li>放置转子到顶针（如果尚未在顶针从步骤6.5.6）。 </li><li>在春/球座滑动法兰/顶针总成。定向，使得该组螺丝中的尖齿当阀被连接到腔室将被朝下的凸缘。 </li><li>使用¼-28的螺栓和螺母，凸缘固定到阀门。 </li><li>关闭阀门。 </li><li>取下磁铁和磁带持球。 </li></ol></li></ol> 7.组装集装箱<ol><li>切酯泡沫到装运容器的尺寸。泡沫的厚度将取决于容器的高度。放置7.6厘米的底部泡沫的最小厚度。 图7示出了泡沫组件。 </li><li>放置PE发泡缺口在T之上他酯泡沫。 </li><li>放置酯泡沫层在盖。的最小厚度应该是7.6厘米。 图8示出了弹簧输送机构的最终位置。使用清洁的铝箔和塑料端盖（即与阀来），以保护所述阀口的开口端装运期间。 </li></ol> 8.使用Spring的传输机制<ol><li>安装和悬挂转子: 注意: 图9示出了具有附接的头部安装的弹簧传输机制。第一步是从装运容器中的弹簧传输机制。在下面，假定读者熟悉与纺丝转子轨距的操作。操作控制器的详细信息可以在控制器的用户手册中找到。它还假定读者熟悉的高真空技术。 <ol><li>从春天传输机制的开放端口取下端盖和贴膜。附加开放端口为DN 40（CF 2.75"）上使用新的铜或镀银铜垫片和一个1/4-28螺栓集。阀的方向将取决于尖齿的取向的真空室端口，恰当取向示于图9，与向下设置的螺钉点的齿。在顶针滑头部，顶针的方向应是垂直的2°范围内。检查取向的水平。 </li><li>抽空真空腔到小于10 -3帕。慢慢打开弹簧传输机制阀门。 </li><li>连接头到控制器。打开控制器，并暂停了球。 </li></ol></li><li>德安装​​弹簧传输机制<ol><li>使用电子控制器去停止该转子。关闭控制器。 </li><li>关闭弹簧传输机制阀门。 </li><li>删除头。 </li><li>泄真空室中。 </li><li>删除由弹簧传输机制未抽薹阀门从真空室端口。 </li><li>放置清洁箔和在弹簧输送机构的开放口的塑料端帽。在切口处弹簧传输机制的集装箱。 </li></ol></li></ol>

<ol>
	<li>Fremerey, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+spinning+rotor+gauge.">The spinning rotor gauge.</a> J. Vac. Sci. Technol. A. 3 (3), 1715-1720 (1985).</li><li>Jousten, K., Jousten, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+13,+Total+Pressure+Vacuum+Gauges.">Chapter 13, Total Pressure Vacuum Gauges.</a> Handbook of Vacuum Technology. , 573-583 (2008).</li><li>Berg, R. F., Fedchak, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NIST+Calibration+Services+for+Spinning+Rotor+Gauge+Calibrations.">NIST Calibration Services for Spinning Rotor Gauge Calibrations.</a> NIST Special Publication. , 250-293 (2015).</li><li>Messer, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intercomparison+of+Nine+National+High-vacuum+Standards+under+the+Auspices+of+the+Bureau+International+des+Poids+et+Mesures.">Intercomparison of Nine National High-vacuum Standards under the Auspices of the Bureau International des Poids et Mesures.</a> Metrologia. 26, 183-195 (1989).</li><li>Jousten, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Results+of+the+regional+key+comparison+Euromet.M.P-K1.b+in+the+pressure+range+from+3+x+10-4+Pa+to+0.9+Pa.">Results of the regional key comparison Euromet.M.P-K1.b in the pressure range from 3 x 10-4 Pa to 0.9 Pa.</a> Metrologia. 42 (1A), 07001 (2005).</li><li>Jousten, K., Santander Romero, L. A., Torres Guzman, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Results+of+the+key+comparison+SIM-Euromet.M.P-BK3+(bilateral+comparison)+in+the+pressure+range+from+3+x+10-4+Pa+to+0.9+Pa.">Results of the key comparison SIM-Euromet.M.P-BK3 (bilateral comparison) in the pressure range from 3 x 10-4 Pa to 0.9 Pa.</a> Metrologia. 42 (1A), 07002 (2005).</li><li>Yoshida, H., Arai, K., Akimichi, H., Hong, S. S., Song, H. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Final+report+on+key+comparison+APMP.M.P-K3:+Absolute+pressure+measurements+in+gas+from+3+x+10-6+Pa+to+9+x+10-4+Pa.">Final report on key comparison APMP.M.P-K3: Absolute pressure measurements in gas from 3 x 10-6 Pa to 9 x 10-4 Pa.</a> Metrologia. 48 (1A), 07013 (2011).</li><li>Fedchak, J. A., Bock, T. h., Jousten, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bilateral+key+comparison+CCM.P-K3.1+for+absolute+pressure+measurements+from+3+x+10-6+Pa+to+9+x+10-4+Pa.">Bilateral key comparison CCM.P-K3.1 for absolute pressure measurements from 3 x 10-6 Pa to 9 x 10-4 Pa.</a> Metrologia. 51 (1A), 07005 (2014).</li><li>Fedchak, J. A., Arai, K., Jousten, K., Setina, J., Yoshida, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recommended+practices+for+the+use+of+spinning+rotor+gauges+in+inter-laboratory+comparisons.">Recommended practices for the use of spinning rotor gauges in inter-laboratory comparisons.</a> Measurement. 66, 176-183 (2015).</li><li>Rohl, P., Jitschin, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Performance+of+the+spinning+rotor+gauge+with+a+novel+transport+device+as+a+transfer+standard+for+high+vacuum.">Performance of the spinning rotor gauge with a novel transport device as a transfer standard for high vacuum.</a> Vacuum. 38 (7), 507-509 (1988).</li><li>Fedchak, J. A., Scherschligt, J., Sefa, M., Phandinh, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Building+a+spring-transport+package+for+spinning+rotor+gauges.">Building a spring-transport package for spinning rotor gauges.</a> J. Vac. Sci. Technol. A. 33 (3), (2015).</li><li>Hussey, D. S., Jacobson, D. L., Arif, M., Coakley, K. J., Vecchia, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Situ+Fuel+Cell+Water+Metrology+at+the+NIST+Neutron+Imaging+Facility.">In Situ Fuel Cell Water Metrology at the NIST Neutron Imaging Facility.</a> J. Fuel Cell Sci. Technol. 7 (2), 021024 (2010).</li><li>Chang, R. F., Abbott, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+affecting+the+reproducibility+of+the+accommodation+coefficient+of+the+spinning+rotor+gauge.">Factors affecting the reproducibility of the accommodation coefficient of the spinning rotor gauge.</a> J. Vac. Sci. Technol. A. 25 (6), 1567-1576 (2007).</li></ol>

Commercial equipment is identified in this paper to foster understanding and does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it necessarily imply that the materials or equipment identified are necessarily the best available for the purpose. The authors have nothing else to disclose.

的目的是设计具有足够的保持力，使得转子将在运输期间保持固定的弹簧输送机构。设计一个健壮弹簧输送机构是不够的，以确保该转子将保持固定，因为，例如，从高大的高度机构落下到硬表面上能产生巨大的冲击。在转子上的力可通过在包装内包装弹簧传输机构，使得它轻轻地减速过的距离，从而降低了冲击大大降低。脉冲力由对象经历时被丢弃被称为休克，而由于重力，G加速度计通...

纺纱转子计（SRG）是用于确定在1.0×10 -4 Pa至1.0的范围内的真空压力的高真空计帕，它本质上是一个旋转的钢球即两个永久磁铁之间暂停。电磁铁被用来旋转或"自旋向上"，球在一定频率（通常为410赫）;然后将球被允许自由旋转，但旋转速率会降低，因为在真空系统与球表面气体分子碰撞的随时间。真空压力因此相关于钢球或转子的减速率图1示出了开关磁阻发电机的基本要素:转子，顶针，头部与连接电缆和电子控制器。转子，或球，在操作过程中包含在该顶针和通常不被处理，也不是对SRG用户可见。顶针被连接到真空系统中。为了操作开关磁阻发电机，磁头滑过套管。该头包含两个永久磁铁和多套用于垂直和水平稳定导线线圈，驱动转子，并且感测的旋转。电子控制器解释从传感线圈，使得压力测量可以由该信号。对于理想的表面状态的转子，该减速度与由基本物理真空压力。使绝对压力测量值使用SRG，校准因子，称为有效调节系数，必须确定。有效住宿系数取决于转子的实际表面的条件，如粗糙度，吸附气体和划痕。这些因素趋向于在其使用过程中是稳定的。自力更生团体的更多细节可以在其他参考文献中找到1 - 3 SRG的是在需要绝对真空的测量应用中。例如，校准经常实验室使用自力更生团体作为绝对真空的标准。在这种情况下，高真空计是由他们的阅读比较的SRG的校准。反过来，SRG标准必须定期通过运送SRG到主校准实验室具有其住宿系数重新确定校准。主要校准实验室通常是国家计量研究所，如美国国家标准与技术研究院（NIST）。主实验室由其读数比较初级真空标准确定SRG住宿系数，然后将SRG返回到"辅助"校准实验室。 SRG的也用作用于校准实验室或国家计量研究所之间的标准比较的传输标准。在本申请中，SRG在各种实验室之间国内或国际运输4 - 8装运期间，事件可以发生改变的调节系数。成sh之前双模接收机设备中，转子必须解除暂停和头部被移除;转子然后搁置在顶针的内壁。在运输过程中，转子表面受到从转子和顶针之间的机械作用而发生变化的振动和冲击，或表面可以改变由于转子的暴露于大气气体和湿度。这些变化影响了调节系数的长期稳定性。理想的是，转子应保持在真空和运输过程中固定不动。 从历史上看，自力更生团体已被用作在国家计量机构，其中自力更生小组在国际上运送许多次的各种机构之间。9在早期键比较中真空标准的键比较传输标准，它被发现的长期稳定性SRG住宿系数可以通过利用弹簧的运输机制都固定在转子，并保持它在真空ð得到改善uring运输。1,10此后，弹簧输送机构已在国际关键比多次使用。最近对历史数据的研究表明，90％的这些比较具有稳定性优于0.75％和70％的0.5％的稳定性。9因此，使用弹簧输送机构将在大多数情况下，产生一个稳定的即以上足以满足大多数的应用程序。 到现在为止，很少有指导在文献中关于如何建立一个弹簧传输机制。这些装置的早期版本已经知道不能充分固定所述转子，由于被充分设计的鲁棒性的组合，并且在运输过程中被误操作。这些早期的经验教训表明，既要建立一个强大的弹簧传输机制，并妥善包装它在运输过程中减少震动的方式是很重要的。这后一点是至关重要的，但常常被忽视。在这里，我们将describE在除了正确构造运输包装一个强大的弹簧传输机制的建设。我们的设计是基于一些简单的，经测试，工程原理，使在运输过程中最小化失效的可能性持久弹簧传输包的结构。我们还描述了我们的设计的可靠性测试。的测试方法的其它细节可在Fedchak 等中找到。 （2015）。11

<table>
	<tbody>
		<tr>
			<td>Spring, 3 N/m</td>
			<td>Lee Spring (www.leespring.com)</td>
			<td>LC 042C 18 S316</td>
			<td>Outside diameter 0.240 in, Wire Diameter 0.042 in, Rate 17.1 lb/in, Free Length 2.25 in, Number of Coils 29.3&#160;&#160;</td>
		</tr>
		<tr>
			<td>8-32 threaded rod, 316 stainless steel</td>
			<td>McMaster-Carr (www.mcmaster.com)</td>
			<td>90575A260</td>
			<td>Type 316 Stainless Steel Fully Threaded Stud 8-32 Thread, 3&#34; Length.&#160; Cut to length specified in protocol</td>
		</tr>
		<tr>
			<td>standoffs, 8-32 Screw Size</td>
			<td>McMaster-Carr (www.mcmaster.com)</td>
			<td>91125A140</td>
			<td>18-8 Stainless Steel Female Threaded Round Standoff, 1/4&#34; OD, 1/4&#34; Length, 8-32 Screw Size</td>
		</tr>
		<tr>
			<td>nuts, 8-32</td>
			<td>McMaster-Carr (www.mcmaster.com)</td>
			<td>90205A309</td>
			<td>316 SS Undersized Machine Screw Hex Nut 8-32 Thread Size, 1/4&#34; Width, 3/32&#34; Height</td>
		</tr>
		<tr>
			<td>Split Lock-Washers, 316 Stainless Steel</td>
			<td>McMaster-Carr (www.mcmaster.com)</td>
			<td>92147A425</td>
			<td>Type 316 Stainless Steel Split Lock Washer NO. 8 Screw Size, .3&#34; OD, .04&#34; min Thick</td>
		</tr>
		<tr>
			<td>Steel Rotor</td>
			<td>McMaster-Carr (www.mcmaster.com)</td>
			<td>9292K38</td>
			<td>&#160;Bearing-Quality E52100 Alloy Steel, Hardened Ball, 4.5 mm Diameter</td>
		</tr>
		<tr>
			<td>Right-Angle Valve</td>
			<td>VAT Valve (www.vatvalve.com)</td>
			<td>54132-GE02-0001</td>
			<td>Easy-close all-metal angle valve, DN 40 (1.5&#34;)</td>
		</tr>
		<tr>
			<td>Shipping Container</td>
			<td>Allcases, Reekstin &#38; Associates (www.allcases.com)</td>
			<td>REAL1616-1205</td>
			<td>Zinc Hardware w/Zinc Handles, Rotationally Molded, light-weight, high-impact, Polyethylene Case with protected recessed hardware.&#160; 15.75&#34; X 15.88&#34; X 16.45&#34;</td>
		</tr>
		<tr>
			<td>Ester Foam</td>
			<td>Carry Cases Plus (www.carrycasesplus.com)</td>
			<td>ES-PAD 3&#34; Thick</td>
			<td>3&#34; Thick, 2lb Charcoal Ester Foam Pad, 24&#34; x 27&#34;.&#160;</td>
		</tr>
		<tr>
			<td>Ester Foam</td>
			<td>Carry Cases Plus (www.carrycasesplus.com)</td>
			<td>ES-PAD 1&#34; Thick</td>
			<td>1&#34; Thick, 2lb Charcoal Ester Foam Pad, 24&#34; x 27&#34;.&#160;</td>
		</tr>
		<tr>
			<td>Egg-carton ester foam</td>
			<td>Carry Cases Plus (www.carrycasesplus.com)</td>
			<td>ES-CONV</td>
			<td>ES-CONV, 2lb, 24&#34; x 27&#34; x 1 1/2&#34;.&#160; &#34;egg-crate&#34; ester foam.&#160;</td>
		</tr>
		<tr>
			<td>Foam Cutout, PE foam</td>
			<td>Willard Packaging Co. (www.willardpackaging.com)</td>
			<td></td>
			<td>Custom Foam Cutout.</td>
		</tr>
		<tr>
			<td>Spinning Rotor Gauge&#160;</td>
			<td>MKS Instruments (www.mks.com)</td>
			<td>SRG-3</td>
			<td>Controller, head, and thimble.&#160; Custom thimble must be used for the spring-transport mechanism</td>
		</tr>
		<tr>
			<td>Custom thimble</td>
			<td>MDC vacuum Inc. (www.mdcvacuum.com)</td>
			<td></td>
			<td>drawing must be submitted for custom part</td>
		</tr>
		<tr>
			<td>Detergent</td>
			<td>Fisher Scientific Co (www.fischersci.com)</td>
			<td>04-320-4</td>
			<td>Sparkleen 1 Detergent</td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Fisher Scientific Co (www.fischersci.com)</td>
			<td>A18-S4</td>
			<td>Acetone (Certified ACS)</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Warner-Graham Company (www.warnergraham.com)</td>
			<td>190 proof USP</td>
			<td>190 Proof USP ethyl alcohol</td>
		</tr>
		<tr>
			<td>Bolt set for valve</td>
			<td>Kurt J. Lesker (www.lesker.com)</td>
			<td>TBS25028125P</td>
			<td>&#160;B,N&#38;W SET,12 POINT,(25)1/4-28X 1.25&#34;FOR 2.75&#34;THRU,SILVER PLAT&#160;</td>
		</tr>
		<tr>
			<td>Silver-plated copper gaskets</td>
			<td>Kurt J. Lesker (www.lesker.com)</td>
			<td>GA-0275LBNSP</td>
			<td></td>
		</tr>
		<tr>
			<td>Spring Assembly (welding)</td>
			<td>Omley Industries, Inc. (www.omley.com)</td>
			<td>N/A</td>
			<td>The machine work and welding were done in NIST&#39;s shop. However, Omley industries was used as an alternative for welding the spring assembly.</td>
		</tr>
	</tbody>
</table>

how to build a vacuum spring-transport package for spinning rotor gauges

纺纱转子计（SRG）是高真空计通常用作1.0×10 -4 Pa的1.0帕的范围内为真空压力仲或传输标准。在本申请中，自力更生团体经常运送到实验室用于校准。运输该改变转子表面状态期间可发生的事件，从而改变校准因子。为了保证校准稳定性，弹簧输送机构通常用于固定转子和运输过程中保持在真空下。同样重要的是运输使用的包装设计在运输过程中，以减少损坏的风险弹簧传输机制。在这份手稿，详细描述了如何建立一个强大的弹簧传输机制和集装箱给出。这些一起形成一个弹簧传输包。弹簧运输包装设计，使用滴试验测试和性能被认为是优良的。本弹簧运输ORT机构设计使经历的几百克的冲击时固定在转子（G = 9.8Hz米/秒2，并且由于重力的加速度），而运输容器保证该机构将不会遇到冲击时常见大于约100 g以上航运事故（如行业标准定义）。

所有商业SRG的部件的示于图1中 ，这包括包含用于悬浮液和拾取永久磁铁和电线线圈的转子，顶针，头部，和电子控制器。小弹簧所示（ 图1c）是用来保持在顶针球;该保持弹簧不会在弹簧输送机构使用。商用控制器和头在弹簧输送机构使用。从商业顶针齿可能会被删除并在弹簧的传输机制使用，或者这些简单零件的副本可以制造。转子也可使用，...

Watch this Scientific Journal Video about How to Build a Vacuum Spring-transport Package for Spinning Rotor Gauges at JoVE.com

How to Build a Vacuum Spring-transport Package for Spinning Rotor Gauges

如何建立一个真空Spring的运输包装为纺转子规

Here we describe how to build a robust spring-transport mechanism for a spinning rotor gauge. This device securely immobilizes the rotor and keeps it under vacuum during transportation. We also describe packaging that minimizes the risk of damage during transport. Tests show our design works for typical shocks during transport.

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to ...

how-to-build-vacuum-spring-transport-package-for-spinning-rotor

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

9.1K 次观看.  National Institute of Science and Technology. Here we describe how to build a robust spring-transport mechanism for a spinning rotor gauge. This device securely immobilizes the rotor and keeps it under vacuum during transportation. We also describe packaging that minimizes the risk of damage during transport. Tests show our design works for typical shocks during transport.

视频: How to Build a Vacuum Spring-transport Package for Spinning Rotor Gauges

High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extreme Conditions

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their electronic properties. The application of high pressure enables one to synthesize new materials, but the response of known materials to high pressure is a very useful tool for studying their electronic structure and developing theories. For example, high-pressure synthesis might be at the origin of life; and understanding the behavior of small molecules under extreme pressure will tell us more about fundamental processes in our universe. It is no wonder that there has always been great interest in having NMR available at high pressures. Unfortunately, the desired pressures are often well into the Giga-Pascal (GPa) range and require special anvil cell devices where only very small, secluded volumes are available. This has restricted the use of NMR almost entirely in the past, and only recently, a new approach to high-sensitivity GPa NMR, which has a resonating micro-coil inside the sample chamber, was put forward. This approach enables us to achieve high sensitivity with experiments that bring the power of NMR to Giga-Pascal pressure condensed matter research. First applications, the detection of a topological electronic transition in ordinary aluminum metal and the closing of the pseudo-gap in high-temperature superconductivity, show the power of such an approach. Meanwhile, the range of achievable pressures was increased tremendously with a new generation of anvil cells (up to 10.1 GPa), that fit standard-bore NMR magnets. This approach might become a new, important tool for the investigation of many condensed matter systems, in chemistry, geochemistry, and in physics, since we can now watch structural changes with the eyes of a very versatile probe.

Nuclear magnetic resonance is one of the most important spectroscopic tools. Here, the development of a new approach under high pressure, currently up to 10.1 GPa, is presented. This opens a new window into condensed matter physics and chemistry, where high-pressure research is of great importance.

高灵敏度核磁共振的千兆帕斯卡压力:一种新的工具，用于极端条件下探测电子和化工凝聚态的性质

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their ...

科研

工程学

Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their behavior for single stages of a process or even an entire process. For the simulation with occurring particle-particle and particle-wall contacts, the value of the coefficient of restitution is required. It can be determined experimentally. The coefficient of restitution depends on several parameters like the impact velocity. Especially for fine particles the impact velocity depends on the air pressure and under atmospheric pressure high impact velocities cannot be reached. For this, a new experimental setup for free-fall tests under vacuum conditions is developed. The coefficient of restitution is determined with the impact and rebound velocity which are detected by a high-speed camera. To not hinder the view, the vacuum chamber is made of glass. Also a new release mechanism to drop one single particle under vacuum conditions is constructed. Due to that, all properties of the particle can be characterized beforehand.

The coefficient of restitution is a parameter that describes the loss of kinetic energy during collision. Here, a free-fall setup under vacuum conditions is developed to be able to determine the coefficient of restitution parameter for particles in micrometer range with high impact velocities.

实验装置的研制归还系数在真空条件下测量

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their ...

Measurement of Outgassing Rates of Steels

Steels are commonly used materials in the fabrication of vacuum systems because of their good mechanical, corrosion, and vacuum properties. A variety of steels meet the criterion of low outgassing required for high or ultrahigh vacuum applications. However, a given material can present different outgassing rates depending on its manufacturing process or the various pretreatment processes involved during the fabrication. Thus, the measurement of outgassing rates is highly desirable for a specific vacuum application. For this reason, the rate-of-pressure rise (RoR) method is often used to measure the outgassing of hydrogen after bakeout. In this article, a detailed description of the design and execution of the experimental protocol involved in the RoR method is provided. The RoR method uses a spinning rotor gauge to minimize errors that stem from outgassing or the pumping action of a vacuum gauge. The outgassing rates of two ordinary steels (stainless steel and mild steel) were measured. The measurements were made before and after the heat pretreatment of the steels. The heat pretreatment of steels was performed to reduce the outgassing. Extremely low rates of outgassing (on the order of 10&#8722;11 Pa m3 sec&#8722;1 m&#8722;2) can be routinely measured using relatively small samples.

A protocol for the measurement of outgassing rates of hydrogen from ordinary steel vacuum chambers using the rate-of-pressure rise method is presented.

钢的出气率的测量

Steels are commonly used materials in the fabrication of vacuum systems because of their good mechanical, corrosion, and vacuum properties. A variety of ...

Measuring the Densities of Aqueous Glasses at Cryogenic Temperatures

We demonstrate a method for determining the vitreous phase cryogenic temperature densities of aqueous mixtures, and other samples that require rapid cooling, to prepare the desired cryogenic temperature phase. Microliter to picoliter size drops are cooled by projection into a liquid nitrogen-argon (N2-Ar) mixture. The cryogenic temperature phase of the drop is evaluated using a visual assay that correlates with X-ray diffraction measurements. The density of the liquid N2-Ar mixture is adjusted by adding N2 or Ar until the drop becomes neutrally buoyant. The density of this mixture and thus of the drop is determined using a test mass and Archimedes principle. With appropriate care in drop preparation, management of gas above the liquid cryogen mixture to minimize icing, and regular mixing of the cryogenic mixture to prevent density stratification and phase separation, densities accurate to &#60;0.5% of drops as small as 50 pL can readily be determined. Measurements on aqueous cryoprotectant mixtures provide insight into cryoprotectant action, and provide quantitative data to facilitate thermal contraction matching in biological cryopreservation.

A protocol for determining the vitreous phase densities of micro- to pico-liter size drops of aqueous mixtures at cryogenic temperatures is described.

在低温下测量水性玻璃的密度

We demonstrate a method for determining the vitreous phase cryogenic temperature densities of aqueous mixtures, and other samples that require rapid ...

Fabrication and Implantation of Miniature Dual-element Strain Gages for Measuring In Vivo Gastrointestinal Contractions in Rodents.

Gastrointestinal dysfunction remains a major cause of morbidity and mortality. Indeed, gastrointestinal (GI) motility in health and disease remains an area of productive research with over 1,400 published animal studies in just the last 5 years. Numerous techniques have been developed for quantifying smooth muscle activity of the stomach, small intestine, and colon. In vitro and ex vivo techniques offer powerful tools for mechanistic studies of GI function, but outside the context of the integrated systems inherent to an intact organism. Typically, measuring in vivo smooth muscle contractions of the stomach has involved an anesthetized preparation coupled with the introduction of a surgically placed pressure sensor, a static pressure load such as a mildly inflated balloon or by distending the stomach with fluid under barostatically-controlled feedback. Yet many of these approaches present unique disadvantages regarding both the interpretation of results as well as applicability for in vivo use in conscious experimental animal models. The use of dual element strain gages that have been affixed to the serosal surface of the GI tract has offered numerous experimental advantages, which may continue to outweigh the disadvantages. Since these gages are not commercially available, this video presentation provides a detailed, step-by-step guide to the fabrication of the current design of these gages. The strain gage described in this protocol is a design for recording gastric motility in rats. This design has been modified for recording smooth muscle activity along the entire GI tract and requires only subtle variation in the overall fabrication. Representative data from the entire GI tract are included as well as discussion of analysis methods, data interpretation and presentation.

Fabrication and Implantation of Miniature Dual-element Strain Gages for Measuring In Vivo Gastrointestinal Contractions in Rodents.

The in vivo measurement of smooth muscle contractions along the gastrointestinal tract of laboratory animals remains a powerful, though underutilized, technique. Flexible, dual element strain gages are not commercially available and require fabrication. This protocol describes the construction of reliable, inexpensive strain gages for acute or chronic implantation in rodents.

的微型双元应变计测量加工和植入<em&gt;体内</em&gt;胃肠收缩鼠害。

Gastrointestinal dysfunction remains a major cause of morbidity and mortality. Indeed, gastrointestinal (GI) motility in health and disease remains an ...

生物工程

Magnet Assisted Composite Manufacturing: A Flexible New Technique for Achieving High Consolidation Pressure in Vacuum Bag/Lay-Up Processes

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed magnet assisted composite manufacturing (MACM) technique. In this technique, permanent magnets are utilized to apply a sufficiently high consolidation pressure during the curing stage. To enhance the intensity of the magnetic field, and thus, to increase the magnetic compaction pressure, the magnets are placed on a magnetic top plate. First, the entire procedure of preparing the composite lay-up on a magnetic bottom steel plate using the conventional wet lay-up vacuum bag process is described. Second, placement of a set of Neodymium-Iron-Boron permanent magnets, arranged in alternating polarity, on the vacuum bag is illustrated. Next, the experimental procedures to measure the magnetic compaction pressure and volume fractions of the composite constituents are presented. Finally, methods used to characterize microstructure and mechanical properties of composite laminates are discussed in detail. The results prove the effectiveness of the MACM method in improving the quality of wet lay-up vacuum bag laminates. This method does not require large capital investment for tooling or equipment and can also be used to consolidate geometrically complex composite parts by placing the magnets on a matching top mold positioned on the vacuum bag.

A new technique for applying consolidation pressure on the vacuum bag lay-up to fabricate composite laminates is described. The goal of this protocol is to develop a simple, cost-effective technique to improve the quality of laminates fabricated by the wet lay-up vacuum bag method.

磁铁辅助复合制造: 真空袋/糊化过程中实现高固结压力的一种柔性新技术

This work demonstrates a protocol to improve the quality of composite laminates fabricated by wet lay-up vacuum bag processes using the recently developed ...

Building Langmuir Probes and Emissive Probes for Plasma Potential Measurements in Low Pressure, Low Temperature Plasmas

Langmuir probes have long been used in experimental plasma physics research as the primary diagnostic for particle fluxes (i.e., electron and ion fluxes) and their local spatial concentrations, for electron temperatures, and for electrostatic plasma potential measurements, since its invention by Langmuir in the early 1920s. Emissive probes are used for measuring plasma potentials. The protocols exhibited in this work serve to demonstrate how these probes may be built for use in a vacuum chamber in which a plasma discharge may be confined and sustained. This involves vacuum techniques for building what is essentially an electrical feedthrough, one that is rotatable and translatable. Certainly, complete Langmuir probe systems may be purchased, but they can also be built by the user at considerable cost savings, and at the same time be more directly adapted to their use in a particular experiment. We describe the use of Langmuir probes and emissive probes in mapping the electrostatic plasma potential from the body of the plasma up to the sheath region of a plasma boundary, which in these experiments&#160;is created by a negatively biased electrode immersed within the plasma, in order to compare the two diagnostic techniques and assess their relative advantages and weaknesses. Although Langmuir probes have the advantage of measuring the plasma density and electron temperature most accurately, emissive probes can measure electrostatic plasma potentials more accurately throughout the plasma, up to and including the sheath region.

The main goal of this work is to make it easier for research groups unfamiliar with Langmuir probes and emissive probes to use them as plasma diagnostics, especially near plasma boundaries. We do this by demonstrating how to build the probes from readily available materials and supplies.

构建朗缪尔探头和发射探头，用于低压、低温等离子体中的等离子体电位测量

Langmuir probes have long been used in experimental plasma physics research as the primary diagnostic for particle fluxes (i.e., electron and ion fluxes) ...

High-Temperature and High-Pressure In situ Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy

Nuclear magnetic resonance (NMR) spectroscopy represents an important technique to understand the structure and bonding environments of molecules. There exists a drive to characterize materials under conditions relevant to the chemical process of interest. To address this, in situ high-temperature, high-pressure MAS NMR methods have been developed to enable the observation of chemical interactions over a range of pressures (vacuum to several hundred bar) and temperatures (well below 0 &#176;C to 250 &#176;C). Further, the chemical identity of the samples can be comprised of solids, liquids, and gases or mixtures of the three. The method incorporates all-zirconia NMR rotors (sample holder for MAS NMR) which can be sealed using a threaded cap to compress an O-ring. This rotor exhibits great chemical resistance, temperature compatibility, low NMR background, and can withstand high pressures. These combined factors enable it to be utilized in a wide range of system combinations, which in turn permit its use in diverse fields as carbon sequestration, catalysis, material science, geochemistry, and biology. The flexibility of this technique makes it an attractive option for scientists from numerous disciplines.

The molecular structures and dynamics of solids, liquids, gases, and mixtures are of critical interest to diverse scientific fields. High-temperature, high-pressure in situ MAS NMR enables detection of the chemical environment of constituents in mixed phase systems under tightly controlled chemical environments.

高温高压原位魔角旋转核磁共振光谱

Nuclear magnetic resonance (NMR) spectroscopy represents an important technique to understand the structure and bonding environments of molecules. There ...

化学

Fabrication of Small Caliber Stent-grafts Using Electrospinning and Balloon Expandable Bare Metal Stents

Stent-grafts are widely used for the treatment of various conditions such as aortic lesions, aneurysms, emboli due to coronary intervention procedures and perforations in vasculature. Such stent-grafts are manufactured by covering a stent with a polymer membrane. An ideal stent-graft should have a biocompatible stent covered by a porous, thromboresistant, and biocompatible polymer membrane which mimics the extracellular matrix thereby promoting injury site healing. The goal of this protocol is to manufacture a small caliber stent-graft by encapsulating a balloon expandable stent within two layers of electrospun polyurethane nanofibers. Electrospinning of polyurethane has been shown to assist in healing by mimicking native extracellular matrix, thereby promoting endothelialization. Electrospinning polyurethane nanofibers on a slowly rotating mandrel enabled us to precisely control the thickness of the nanofibrous membrane, which is essential to achieve a small caliber balloon expandable stent-graft. Mechanical validation by crimping and expansion of the stent-graft has shown that the nanofibrous polyurethane membrane is sufficiently flexible to crimp and expand while staying patent without showing any signs of tearing or delamination. Furthermore, stent-grafts fabricated using the methods described here are capable of being implanted using a coronary intervention procedure using standard size guide catheters.

In the protocol, we present a method to manufacture a small caliber stent-graft by sandwiching a balloon expandable stent between two electrospun nanofibrous polyurethane layers.

小口径支架移植物使用静电及球囊扩张裸金属支架的制作

Stent-grafts are widely used for the treatment of various conditions such as aortic lesions, aneurysms, emboli due to coronary intervention procedures and ...

医学

Combining 3D-Printing and Electrospinning to Manufacture Biomimetic Heart Valve Leaflets

Electrospinning has become a widely used technique in cardiovascular tissue engineering as it offers the possibility to create (micro-)fibrous scaffolds with adjustable properties. The aim of this study was to create multilayered scaffolds mimicking the architectural fiber characteristics of human heart valve leaflets using conductive 3D-printed collectors.
Models of aortic valve cusps were created using commercial computer-aided design (CAD) software. Conductive polylactic acid was used to fabricate 3D-printed leaflet templates. These cusp negatives were integrated into a specifically designed, rotating electrospinning mandrel. Three layers of polyurethane were spun onto the collector, mimicking the fiber orientation of human heart valves. Surface and fiber structure was assessed with a scanning electron microscope (SEM). The application of fluorescent dye additionally permitted the microscopic visualization of the multilayered fiber structure. Tensile testing was performed to assess the biomechanical properties of the scaffolds.
3D-printing of essential parts for the electrospinning rig was possible in a short time for a low budget. The aortic valve cusps created following this protocol were three-layered, with a fiber diameter of 4.1 &#177; 1.6 &#181;m. SEM imaging revealed an even distribution of fibers. Fluorescence microscopy revealed individual layers with differently aligned fibers, with each layer precisely reaching the desired fiber configuration. The produced scaffolds showed high tensile strength, especially along the direction of alignment. The printing files for the different collectors are available as Supplemental File 1, Supplemental File 2, Supplemental File 3, Supplemental File 4, and Supplemental File 5.
With a highly specialized setup and workflow protocol, it is possible to mimic tissues with complex fiber structures over multiple layers. Spinning directly on 3D-printed collectors creates considerable flexibility in manufacturing 3D shapes at low production costs.

The presented method offers an innovative way for engineering biomimetic fiber structures in three-dimensional (3D) scaffolds (e.g., heart valve leaflets). 3D-printed, conductive geometries were used to determine shape and dimensions. Fiber orientation and characteristics were individually adjustable for each layer. Multiple samples could be manufactured in one setup.

结合3D打印和静电纺丝来制造仿生心脏瓣膜传单

Electrospinning has become a widely used technique in cardiovascular tissue engineering as it offers the possibility to create (micro-)fibrous scaffolds ...