DOCSLIB.ORG

High-Throughput Measurement of the Contact Resistance of Metal Electrode Materials and Uncertainty Estimation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
High-Throughput Measurement of the Contact Resistance of Metal Electrode Materials and Uncertainty Estimation electronics Article High-Throughput Measurement of the Contact Resistance of Metal Electrode mAterials and Uncertainty Estimation Chao Zhang and Wanbin Ren * School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150001, China; [email protected] * Correspondence: [email protected] Received: 30 October 2020; Accepted: 4 December 2020; Published: 6 December 2020 Abstract: Low and stable contact resistance of metal electrode mAterials is mAinly demanded for reliable and long lifetime electrical engineering. A novel test rig is developed in order to realize the high-throughput measurement of the contact resistance with the adjustable mechanical load force and load current. The contact potential drop is extracted accurately based on the proposed periodical current chopping (PCC) method in addition to the sliding window average filtering algorithm. The instrument is calibrated by standard resistors of 1 mW, 10 mW, and 100 mW with the accuracy of 0.01% and the associated measurement uncertainty is evaluated systematically. Furthermore, the contact resistance between standard indenter and rivet specimen is measured by the commercial DMM-based instruments and our designed test rig for comparison. The variations in relative expanded uncertainty of the measured contact resistance as a function of various mechanical load force and load current are presented. Keywords: electrode mAterial; high-throughput characterization; contact resistance; measurement; uncertainty estimation 1. Introduction Metal electrode mAterials are widely used in the electrical and electronic engineering for conducting and/or switching current, such as connectors [1], electromechanical devices [2], thin-film devices [3], microelectromechanical system [4], and switchgear [5], etc. The roughness of the mAterial surfaces causes only small peaks or asperities within the apparent surface to be in contact. The induced constriction resistance and film resistance together mAke up the contact resistance. Today, ‘High performance and high reliability’ of electromechanical devices and electronic components that are used in the high-end equipment mAnufacturing industry is always required. Therefore, the optimal selection method for supporting electrode mAterial and contact resistance measuring method are needed to mAke them perfect. For example, the contact resistance measurement has been successfully used to evaluate the conditions of mAin contacts and arcing contacts without dismantling the high voltage SF6 circuit breaker [6]. Additionally, it could be used to estimate the contact a-spot temperature, and further judge the contact welding situation by classical Voltage–Temperature theory [5,7]. Particularly, the contact resistance results could be selected as the criteria of contact mAterial surface quality, including roughness, hardness, or contamination situation [8,9]. The value of contact resistance is normally very small, ranging from microohms to a few milliohms in cases of practical interest. However, for contacts with worn surface or corroded or contaminated surface, the contact resistance dramatically increases into the scale of ohms or higher [10–12]. The general described contact resistance test methods are characterized as four-terminal Kelvin configuration. Electronics 2020, 9, 2079; doi:10.3390/electronics9122079 www.mdpi.com/journal/electronics Electronics 2020, 9, 2079 2 of 13 The challenge of measuring microohm scales of contact resistance is that the value is so low level that overwhelmed by the diverse noise easily. Particularly, the thermal potentials are the mAin source of influencing the measured voltage signals. Either AC or DC test currents mAy be used, but the most general method of eliminating the effects of thermal potentials is to mAke forward-and-reverse-current readings and calculating resistance. The measurement accuracy of contact resistance could reach up to 0.1 µW by using the innovative methods [13–17]. The scientific instruments for single pair contact mAterial are developed by mAny researchers in order to investigate and evaluate the electrical contact characteristics. Some instruments also include fretting mode and corrosion film current-voltage (I-V) characteristics and environmental atmosphere application [13]. Particularly, the nano-scale electrical contact resistance tool (nanoECR, BRUKER, Minneapolis, MN, USA), provide a powerful solution for simultaneous, in-situ electrical and mechanical measurements [17]. Unfortunately, the mentioned contact resistance measurement apparatus are always based on the commercial digital multimeter for the research work in the laboratory. Additionally, only one contact pair could be tested in one experiment so that the test efficiency is very low. Nevertheless, the loading range of the contact force is too large (up to 1 ton) and the loading accuracy ( 1 kg) is too low. These could not meet the contact resistance measurement requirements ± within 500 g contact force for batches of rivet contacts in engineering. Consequently, the mAin goal of the present work is to fill this gap by developing an apparatus which allow simultaneous automated measurements of contact force and contact resistance with the variable contact current and open voltage. This apparatus should also provide motion mechanism for precise positioning among samples and associated control programme which satisfy the high-throughput measurement. In this paper, we design a novel test rig (including the circuit and associated programme for measuring the low value contact resistance, the electrical actuators combinations and the auxiliary optical observation unit) that could meet the mentioned requirement. A suit of DC standard resistors are selected as the calibration source for minimizing the measurement error. Further, the contact resistance results of electrode mAterials are measured and compared with the use of our designed test rig and commercial Digital Multimeter instruments simultaneously. Finally, the uncertainty of measured contact resistance is estimated and analysed in detail. 2. Description of the New Designed Test Rig In general, the new designed test rig allows studying the high-throughput measurement of contact resistance between two electrode mAterials under the selectable load force and load current. It was designed to fulfill the goals mentioned in the introduction: Variable load forces to achieve pure elastic or elastic–plastic contact mode. • Different electrical current levels to discriminate the roles of electrical loads and mechanical loads • in contact resistance. Highly efficient test for batches of rivet contacts: 10 s for single contact pair and 2 min for mAximum • 12 contact pairs automatically. Measurement principle conforming to the regulation of Standard Test Methods ASTM B539-2013 • and ASTM B667-2014. 2.1. Mechanical Structures The designed mechanical structure (shown in Figure1) is placed in a dust-tight transparent Plexiglas housing which is secured on a vibration isolation base to ensure the stability of the measurement. The rivet samples holder is fixed on the base. Furthermore, there are multiple workstations in the holder which could clamp mAximum 12 rivets simultaneously in one row. The clamping structure is designed suitable for different contact dimensions. The minimum shank diameter of rivet samples should be no less than 1 mm. The counterpart probe could be a silver palladium AgPd alloy indenter with 10 µm gold coating (hemispherical shape, 0.5 mm diameter) or Electronics 2020, 9, x FOR PEER REVIEW 3 of 14 Electronics 2020, 9, x FOR PEER REVIEW 3 of 14 palladiumElectronics 2020 AgPd, 9, 2079 alloy indenter with 10 μm gold coating (hemispherical shape, 0.5 mm diameter)3 of or 13 apalladium mated rivet. AgPd The alloy roughness indenter of thewith indenter 10 μm tipgold is coatingmeasured (hemispherical by a con-focal shape, optical 0.5 microscope mm diameter) (LEXT or 3000,a mated Olympus, rivet. The Tokyo, roughness Japan) of and the the indenter surface tip roughness is measured (SRa) by isa con-focal0.4 μm, calculated optical microscope from a scan (LEXT size a mAted rivet. The roughness of the indenter tip is measured by a con-focal optical microscope (LEXT of3000, 50 μOlympus,m × 50 μ m.Tokyo, Figure Japan) 2 schematically and the surface shows roughness the four (SRa)-wire is measurement 0.4 μm, calculated setup, from including a scan sizethe 3000, Olympus, Tokyo, Japan) and the surface roughness (SRa) is 0.4 µm, calculated from a scan size probeof 50 holderμm × 50 structure μm. Figure and the2 schematically rivet clamping shows struct theure four of one-wire measurement measurement workstation. setup, including It is noted the of 50 µm 50 µm. Figure2 schematically shows the four-wire measurement setup, including the thatprobe the holder surfaces× structure of components and the rivetwithin clamping the applied struct currenture of oneand measurementtest voltage circuits workstation. are electroplated It is noted probe holder structure and the rivet clamping structure of one measurement workstation. It is noted withthat thegold surfaces to reduce of componentsthe connection within resistance. the applied Furthermore, current and the coaxialtest voltage shielded circuits lines are are electroplated selected to that the surfaces of components within the applied current and test voltage circuits are electroplated reducewith gold the tointerference reduce the from connection external resistance. signals. The Furthermore, probe is attached the coaxial to a “bow”
Load more

Recommended publications
  • Copyrighted Material - Taylor & Francis
    6 Low-Power Commercial, Automotive, and Appliance Connections AnthonyCopyrighted Lee and George Drew Material - Taylor & Francis They weighed me, dust by dust— They balanced film by film Emily Dickinson COntents 6.1 Introduction ........................................................................................................................ 376 6.2 Connectors ..........................................................................................................................377 6.2.1 Functional Requirements .....................................................................................377 6.2.2 Types of Connectors .............................................................................................. 378 6.2.3 Mechanical Considerations .................................................................................. 381 6.3 Contact Terminals ..............................................................................................................384 6.3.1 Contact Physics ......................................................................................................384 6.3.2 Terminal Types ......................................................................................................384 6.3.3 Other Electrical Contact Parameters ................................................................... 392 6.4 Degradation of Connector Contact ................................................................................. 393 6.4.1 Surface Films .........................................................................................................
    [Show full text]
  • The Pennsylvania State University the Graduate School THE
    The Pennsylvania State University The Graduate School THE EFFECTS OF INTERFACE AND SURFACE CHARGE ON TWO DIMENSIONAL TRANSITORS FOR NEUROMORPHIC, RADIATION, AND DOPING APPLICATIONS A Dissertation in Electrical Engineering by Andrew J. Arnold © 2020 Andrew J. Arnold Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy August 2020 The dissertation of Andrew J. Arnold was reviewed and approved by the following: Thomas Jackson Professor of Electrical Engineering Co-Chair of Committee Saptarshi Das Assistant Professor of Engineering Science and Mechanics Dissertation Advisor Co-Chair of Committee Swaroop Ghosh Assistant Professor of Electrical Engineering Rongming Chu Associate Professor of Electrical Engineering Sukwon Choi Assistant Professor of Mechanical Engineering Kultegin Aydin Professor of Electrical Engineering Head of the Department of Electrical Engineering ii Abstract The scaling of silicon field effect transistors (FETs) has progressed exponentially following Moore’s law, and is nearing fundamental limitations related to the materials and physics of the devices. Alternative materials are required to overcome these limitations leading to increasing interest in two dimensional (2D) materials, and transition metal dichalcogenides (TMDs) in particular, due to their atomically thin nature which provides an advantage in scalability. Numerous investigations within the literature have explored various applications of these materials and assessed their viability as a replacement for silicon FETs. This dissertation focuses on several applications of 2D FETs as well as an exploration into one of the most promising methods to improve their performance. Neuromorphic computing is an alternative method to standard computing architectures that operates similarly to a biological nervous system. These systems are composed of neurons and operate based on pulses called action potentials.
    [Show full text]
  • Finder Relays, General Technical Information
    General technical information Reference standards and values Guidelines for automatic flow solder Unless expressly indicated otherwise, the products shown in this catalogue are designed and manufactured according to the requirements of the processes following European and International Standards: In general, an automatic flow solder process consists of the following - EN 61810-1, EN 61810-2, EN 61810-7 for electromechanical stages: elementary relays - EN 50205 for relays with forcibly guided contacts Relay mounting: Ensure that the relay terminals are straight and enter the - EN 61812-1 for timers PC board perpendicular to the PC board. For each relay, the catalogue - EN 60669-1 and EN 60669-2-2 for electromechanical step relays illustrates the necessary PC board hole pattern (copper side view). Because - EN 60669-1 and EN 60669-2-1 for light-dependent relays, of the weight of the relay, a plated through hole printed circuit board is electronic step relays, light dimmers, staircase switches, recommended to ensure a secure fixation. movement detectors and monitoring relays. Other important standards, often used as reference for specific Flux application: This is a particularly delicate process. If the relay is not applications, are: sealed, flux may penetrate the relay due to capillary forces, changing its - EN 60335-1 and EN 60730-1 for domestic appliances performance and functionality. - EN 50178 for industrial electronic equipments Whether using foam or spray fluxing methods, ensure that flux is applied sparingly and evenly and does not flood through to the component side According to EN 61810-1, all technical data is specified under standard of the PC board.
    [Show full text]
  • Ballistic Transport and Tunneling in Small Systems Are Investigated Theoretically
    BALLISTIC TRANSPORT AND TUNNELING IN SMALL SYSTEMS A- THESIS Submitted to the Deptirirxierii . vry ~*1 W-T» mr»· •1 ' » >·^ T”' · · o .A r ' ' ·' >. C, ' 4 r : ■* .r-» A "X ; rv * ■ f \ : J '■ ·' *1 P.--J i VI-J.W J W < ·'■■ * - w —W-« of Bilkent Unlveijicy iii ?-„rtia^. FulfilJraeni of the Req'iirer-enss for the Degree of Doctor of Pkilospixy A. ERICAN TLKMAN CBBR. 1990 BALLISTIC TRANSPORT AND TUNNELING IN SMALL SYSTEMS A THESIS SUBMITTED TO THE DEPARTMENT OF PHYSICS AND THE INSTITUTE OF ENGINEERING AND SCIENCE OF BILKENT UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSPHY By A. Erkan Tekman October 1990 'TS T 2 fe í> A' J К I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a dissertation for the degree of Doctor of Philosophy. Prof. Salim Çıracı (Supervisor) I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a dissertation for the degree of Doctor of Philosophy. Prof. M. Cerhal Yalabık I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a dissertation for the degree of Doctor of Philosophy. Prof. Şinasi Ellialtioglu I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a dissertation for the degree of Doctor of Philosophy. Assoc. Prof. Atilla Erçelebi I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a dissertation for the degree of Doctor of Philosophy.
    [Show full text]
  • (12) Patent Application Publication (10) Pub. No.: US 2017/0178825 A1 GLOSSER Et Al
    US 20170178825A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2017/0178825 A1 GLOSSER et al. (43) Pub. Date: Jun. 22, 2017 (54) UNIVERSAL CONTACT INPUT Publication Classification SUPPORTNG PROGRAMMABLE WETTING (51) Int. Cl. CURRENT HIH IMO (2006.01) GOIR 31/327 (2006.01) (71) Applicant: GE Intelligent Platforms, Inc., H02. I3/00 (2006.01) Charlottesville, VA (US) HIH I/60 (2006.01) (52) U.S. Cl. (72) Inventors: Richard Joseph GLOSSER, Salem, CPC .......... H0IH I/0015 (2013.01); H0IH I/605 VA (US); Venkatesh J. Hyderabad (IN) (2013.01); G0IR 31/327 (2013.01); H02J 13/00 (2013.01) (21) Appl. No.: 15/327,189 (57) ABSTRACT A system and method according to various embodiments can (22) PCT Fed: Jul. 22, 2014 include a universal contact input status detection circuit. A Voltage source wets a contact with a wetting Voltage. A (86) PCT No.: PCT/US2O14/0476OO current mirror circuit is connected across an input of the contact to provide a constant wetting current over a wide S 371 (c)(1), input Voltage range. The input voltage can be varied over a (2) Date: Jan. 18, 2017 range wide enough to include both AC voltages and DC Voltages. The current mirror circuit maintains the constant wetting current during varying wetting Voltage inputs across Related U.S. Application Data the input of the contact. A wetting Voltage sensor senses the (63) Continuation-in-part of application No. PCT/ wetting voltage provided to the contact so that the status of US2014/047223, filed on Jul. 18, 2014. the contact can be determined.
    [Show full text]
  • Applying Precision Switches
    MICRO SWITCH General Technical Bulletin No. 14 APPLYING PRECISION SWITCHES General Technical Bulletin #14 - Applying Precision Switches TABLE OF CONTENTS INTRODUCTION......................................................................................................................................................................1 BRIEF HISTORY OF THE PRECISION SWITCH ..............................................................................................................1 I. THE MECHANICAL CHARACTERISTICS OF A PRECISION SWITCH...................................................................5 A. MECHANICAL ACTION AND TERMINOLOGY..........................................................................................................................5 B. THE RELATION BETWEEN PLUNGER FORCE AND PLUNGER POSITION....................................................................................6 C. THE RELATION BETWEEN CONTACT FORCE AND PLUNGER POSITION....................................................................................8 D. CONTACT BOUNCE AND TRANSIT TIME................................................................................................................................9 E. POLES, THROWS AND BREAKS............................................................................................................................................10 II. THE ELECTRICAL CHARACTERISTICS OF A PRECISION SWITCH................................................................11 A. THE RESISTANCE OF AN OPEN SWITCH...............................................................................................................................11
    [Show full text]
  • Electrical Contact Bounce and the Control Dynamics of Snap-Action Switch£S
    ELECTRICAL CONTACT BOUNCE AND THE CONTROL DYNAMICS OF SNAP-ACTION SWITCH£S By JOHN WILLIAM McBRIDE ~B.Sc). A thesis submitted to the C.N.A.A for the degree of Doctor of Philosophy, and in partial f~lfilment of the requirements for that degree. Sponsoring Establishment: Plymouth Polytechnic, Plymouth, Devon. Collaborating Establishment: Arrow-Hart lEurope) Ltd, Plymouth, Devon. May 1986. ( \ , I i ·J I 0 .; -: . I DECLARATION I declare that this thesis is the result of my investigations only, and is no[ submitted in candidature for the award of any other degree. During the research programme I was nut registered for the award of any oth~r C.N.A.A or University Degree. ADVANCED STUDIES During the researc~ programme I undertooK a ~ourse of advanced studies. These included the use of the scanning electron microscope, and surface analysis techniques. I also attended several one day seminars, and presented a paper at the 31st Holm conference on e~ectrical contacts. ELECTRICAL CONTACT BOUNCE AND THE CONTROL DYNAMICS OF SNAP-ACTION SWITCHES By, J.W. McBride ABSTRACT Experimental and theoretical studies are made of a typical snap-action rocker switch, to establish the wear mechanisms in the pivoting contact. The rocker switch, used extensive~ in consumer goods, operates in the medium duty current range, (1 - 30 Amps). Highspeed photographic studies have shown that the main cause of wear is arcing, occurri~ during separation and bounce at the pivot contacts. To reduce the bounce a computer-based mathematical model of the system dynamics is developed and opcimised; this results in recommended design changes.
    [Show full text]
  • Electrical Conductivity in Granular Media and Branly's Coherer: A
    Electrical conductivity in granular media and Branly’s coherer: A simple experiment Eric Falcon, Bernard Castaing To cite this version: Eric Falcon, Bernard Castaing. Electrical conductivity in granular media and Branly’s coherer: A simple experiment. 2004. hal-00002394v1 HAL Id: hal-00002394 https://hal.archives-ouvertes.fr/hal-00002394v1 Preprint submitted on 29 Jul 2004 (v1), last revised 16 Nov 2004 (v2) HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Electrical conductivity in granular media and Branly’s coherer: A simple experiment Eric Falcon1, ∗ and Bernard Castaing1 1Laboratoire de Physique, Ecole´ Normale Sup´erieure de Lyon, UMR 5672, 46, all´ee d’Italie, 69 007 Lyon, France (Dated: July 29, 2004) We show how a simple laboratory experiment can be used to exhibit certain electrical transport properties of metallic granular media. At a low critical imposed voltage, a transition from an insulating to a conductive state is observed. This transition comes from an electro-thermal coupling in the vicinity of the microcontacts between grains where microwelding occurs. The apparatus used allows us to obtain an implicit determination of the microcontact temperature, which is analogous to a resistive thermometer.
    [Show full text]
  • Low-Resistance Electrical Contact to Carbon Nanotubes with Graphitic
    12 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 59, NO. 1, JANUARY 2012 Low-Resistance Electrical Contact to Carbon Nanotubes With Graphitic Interfacial Layer Yang Chai, Arash Hazeghi, Kuniharu Takei, Hong-Yu Chen, Student Member, IEEE, Philip C. H. Chan, Fellow, IEEE, Ali Javey, and H.-S. Philip Wong, Fellow, IEEE Abstract—Carbon nanotubes (CNTs) are promising candidates s-CNT and metal electrode [4]–[6]. However, experimental for transistors and interconnects for nanoelectronic circuits. Al- results have shown that the contact resistance is still large for though CNTs intrinsically have excellent electrical conductivity, the CNTs with metallic band structure [2], where the SB should the large contact resistance at the interface between CNT and metal hinders its practical application. Here, we show that electri- not exist at the interface between metallic CNT and metal. cal contact to the CNT is substantially improved using a graphitic This indicates that there is additional contact barrier or series interfacial layer catalyzed by a Ni layer. The p-type semiconduct- resistance for metallic CNT/metal. Recent experimental results ing CNT with graphitic contact exhibits high ON-state conduc- on both semiconducting and metallic CNT devices revealed that tance at room temperature and a steep subthreshold swing in a surface chemistry is very important for forming good electrical back-gate configuration. We also show contact improvement to the semiconducting CNTs with different capping metals. To study the contact between CNT and metal [7], [8]. The metal wetting role of the graphitic interfacial layer in the contact stack, the cap- to the tubular structure of the CNT is imperfect, where the ping metal and Ni catalyst were selectively removed and replaced metal atoms are not fully covered on the CNT surface.
    [Show full text]
  • Keeping Contact. Speciality Lubricants for Electrical Contacts
    your global specialist DetailinformationSpecial knowledge Keeping contact. Speciality lubricants for electrical contacts 1 Why lubricate electrical switches and contacts? 4 What causes the transition resistance in electrical contacts? 5 How do lubricants work on the electrical contact? 6 What to observe in the selection of lubricants for electrical contacts 8 How is the lubricant applied to the contact? 9 How can you find out how effective the lubricant is on the electrical contact? 10 2 B053001002/Edition 11.12, replaces Edition 05.08 Klüber speciality lubricants – always a good choice Quality put to the test Humans and the environment – what really counts – Klüber Lubrication has more than 110 test rigs, which include – Products that last a lifetime and enable minimum-quantity standardised equipment as well as tools Klüber Lubrication lubrication to be used help to save resources and reduce has developed to regularly test the quality of its products. disposal quantities. – Test results prove the high quality level and provide you with a – Speciality lubricants optimised for higher efficiency reduce solid basis for selecting the right lubricant. energy consumption and hence CO2 emission. – You can obtain products made by Klüber Lubrication in con- – Clean, safe products that are easy to handle are the funda- sistent quality at our production plants worldwide. mental criteria used in the lubricant development by the Klüber experts. Benefit from experience KlüberEfficiencySupport - consultation, training & monitoring – Close cooperation
    [Show full text]
  • The Elements.Pdf
    A Periodic Table of the Elements at Los Alamos National Laboratory Los Alamos National Laboratory's Chemistry Division Presents Periodic Table of the Elements A Resource for Elementary, Middle School, and High School Students Click an element for more information: Group** Period 1 18 IA VIIIA 1A 8A 1 2 13 14 15 16 17 2 1 H IIA IIIA IVA VA VIAVIIA He 1.008 2A 3A 4A 5A 6A 7A 4.003 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.941 9.012 10.81 12.01 14.01 16.00 19.00 20.18 11 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB ------- VIII IB IIB Al Si P S Cl Ar 22.99 24.31 3B 4B 5B 6B 7B ------- 1B 2B 26.98 28.09 30.97 32.07 35.45 39.95 ------- 8 ------- 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.47 58.69 63.55 65.39 69.72 72.59 74.92 78.96 79.90 83.80 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr NbMo Tc Ru Rh PdAgCd In Sn Sb Te I Xe 85.47 87.62 88.91 91.22 92.91 95.94 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La* Hf Ta W Re Os Ir Pt AuHg Tl Pb Bi Po At Rn 132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 190.2 195.1 197.0 200.5 204.4 207.2 209.0 (210) (210) (222) 87 88 89 104 105 106 107 108 109 110 111 112 114 116 118 7 Fr Ra Ac~RfDb Sg Bh Hs Mt --- --- --- --- --- --- (223) (226) (227) (257) (260) (263) (262) (265) (266) () () () () () () http://pearl1.lanl.gov/periodic/ (1 of 3) [5/17/2001 4:06:20 PM] A Periodic Table of the Elements at Los Alamos National Laboratory 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Lanthanide Series* Ce Pr NdPmSm Eu Gd TbDyHo Er TmYbLu 140.1 140.9 144.2 (147) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Actinide Series~ Th Pa U Np Pu AmCmBk Cf Es FmMdNo Lr 232.0 (231) (238) (237) (242) (243) (247) (247) (249) (254) (253) (256) (254) (257) ** Groups are noted by 3 notation conventions.
    [Show full text]
  • Copper in Electrical Contacts Copper in Electrical Contacts David Chapman
    Copper in Electrical Contacts Copper in Electrical Contacts David Chapman Copper Development Association Publication No 223 European Copper Institute Publication No Cu0169 July 2015 This publication is a revision by David Chapman of CDA Technical Note TN23 issued in December 1980. This was an edited version of an original script commissioned by Copper Development Association from H W Turner and C Turner of ERA Technology Ltd, Leatherhead Surrey. Copper Development Association is a non-trading organisation that promotes and supports the use of copper based on its superior technical performance and its contribution to a higher quality of life. Its services, which include the provision of technical advice and information, are available to those interested in the utilisation of copper and copper alloys in all their aspects. The Association also provides a link between research and the user industries and is part of an international network of trade associations, the Copper Alliance™. Founded in 1996, ECI is a joint venture between the International Copper Association, Ltd (ICA), headquartered in New York, representing the majority of the world’s leading mining companies, custom smelters and semi-fabricators, and the European copper industry. ECI is also part of the Copper Alliance, an international network of industry associations. Its shared mission is to work, with its members, to defend and grow markets for copper based on its superior technical performance and contributions to a higher quality of life. David Chapman David Chapman was the Electrical Programme Manager for Copper Development Association in the UK, where his main interests included power quality and energy efficiency.
    [Show full text]