Coaxial electrical circuits for interference-free measurements / Shakil Awan, Bryan Kibble and Jürgen Schurr
- IET electrical measurement series ; 13
- Machine generated contents note: 1.1.Interactions between circuits[–]eliminating electrical interference -- 1.1.1.Basic principles -- 1.1.2.An illustrative example[–]using a phase-sensitive detector -- 1.1.3.Diagnostic equipment -- 1.1.4.Isolation -- 1.1.5.Totally isolating transformers and power supplies -- 1.1.6.Isolating a noisy instrument -- 1.1.7.The available methods for isolating outputs -- 1.1.8.Balancing -- 1.1.9.Minimising the effects of insufficiently isolated commercial instruments -- 1.1.10.The 'traditional' approach to DC and low-frequency circuitry versus the current-balanced conductor-pair coaxial approach -- 1.1.11.Thermoelectric emfs -- 1.1.12.Designing temperature-controlled enclosures -- 1.1.13.Ionising radiation (cosmic rays, etc.) -- 1.1.14.Final remarks -- References -- 2.1.General principles -- 2.1.1.The output impedance of a network affects detector sensitivity -- 2.1.2.The sensitivity of detectors to harmonic content -- 2.1.3.Noise and noise matching a detector to a network -- 2.1.4.The concept of a noise figure -- 2.2.Attributes of sources -- 2.3.Properties of different detectors -- 2.3.1.Preamplifiers -- 2.3.2.Wideband (untuned) detectors -- 2.3.3.Narrowband (tuned) detectors -- 2.3.4.Phase-sensitive detectors that employ a switching technique -- 2.3.5.Phase-sensitive detectors employing a modulating technique -- 2.4.Cables and connectors -- References -- 3.1.The coaxial conductor -- 3.1.1.Achieving current equalisation -- 3.1.2.The concept of a coaxial network -- 3.2.Construction and properties of coaxial networks -- 3.2.1.Equalisers in bridge or other measuring networks -- 3.2.2.Assessing the efficiency of current equalisers -- 3.2.3.Single conductors added to an equalised network -- 3.2.4.Other conductor systems having similar properties -- 3.2.5.DC networks -- 3.2.6.The effect of a length of cable on a measured value -- 3.2.7.Tri-axial cable -- References -- 4.1.Improvements in defining what is to be observed or measured -- 4.1.1.Ratio devices -- 4.1.2.Impedance standards -- 4.1.3.Formal representation of circuit diagrams and components -- 5.1.The evolution of a coaxial bridge -- 5.1.1.A simple coaxial bridge as an example of a coaxial network -- 5.2.The validity of lumped component representations -- 5.3.General principles applying to all impedance standards -- 5.3.1.The physical definition of a standard -- 5.3.2.The electrical definition of a standard impedance -- 5.3.3.Two-terminal definition -- 5.3.4.Four-terminal definition -- 5.3.5.Four-terminal coaxial definition -- 5.3.6.Two-terminal-pair definition -- 5.3.7.Three-terminal definition -- 5.3.8.Four-terminal-pair definition -- 5.3.9.Measuring four-terminal-pair admittances in a two-terminal-pair bridge by extrapolation -- 5.3.10.Adaptors to convert a two- or four-terminal definition to a four-terminal-pair definition -- 5.4.The effect of cables connected to the ports of impedance standards -- 5.4.1.The effect of cables on a two-terminal component -- 5.4.2.The effect of cables on a four-terminal coaxial component -- 5.4.3.The effect of cables on a two-terminal-pair component -- 5.4.4.The effect of cables on a four-terminal-pair component -- 5.5.An analysis of conductor-pair bridges to show how the effect of shunt admittances can be eliminated -- 5.5.1.Comparing direct admittances using voltage sources -- 5.6.Combining networks to eliminate the effect of unwanted potential differences -- 5.6.1.The concept of a combining network -- 5.6.2.A general purpose AC combining network and current source -- 5.7.Connecting two-terminal-pair impedances in parallel -- References -- 6.1.The history of impedance standards -- 6.2.The Thompson[–]Lampard theorem -- 6.3.Primary standards of phase angle -- 6.4.Impedance components in general -- 6.4.1.Capacitors -- 6.4.2.Parallel-plate capacitance standard -- 6.4.3.Two-terminal capacitors -- 6.4.4.Three-terminal capacitors -- 6.4.5.Two- and four-terminal-pair capacitors -- 6.4.6.The mechanical construction and properties of various types of capacitors -- 6.4.7.Capacitance standards of greater than 1 [µ]F -- 6.4.8.Voltage dependence of capacitors -- 6.4.9.Resistors -- 6.4.10.T-networks -- 6.4.11.Adding auxiliary components to resistors to reduce their reactive component -- 6.4.12.Mutual inductors: Campbell's calculable mutual inductance standard -- 6.4.13.Self-inductors -- 6.5.Resistors, capacitors and inductors of calculable frequency dependence -- 6.5.1.Resistance standards -- 6.5.2.Haddad coaxial resistance standard -- 6.5.3.A nearly ideal HF calculable coaxial resistance standard -- 6.5.4.A bifilar resistance standard -- 6.5.5.Gibbings quadrifilar resistance standard -- 6.5.6.Bohácek and Wood octofilar resistance standard -- 6.5.7.HF secondary resistance standards -- 6.5.8.HF parallel-plate capacitance standard -- 6.5.9.HF calculable coaxial capacitance standard -- 6.5.10.HF calculable coaxial inductance standard -- 6.5.11.A frequency-independent standard of impedance -- 6.5.12.An ideal standard of impedance of calculable frequency dependence -- 6.6.Quantum Hall resistance -- 6.6.1.Properties of the quantum Hall effect (QHE) and its use as a DC resistance standard -- 6.6.2.The properties and the equivalent circuit of a quantum Hall device -- 6.6.3.Device handling -- 6.7.QHE measured with AC -- 6.7.1.Multiple-series connection scheme -- 6.7.2.A device holder and coaxial leads -- 6.7.3.Active equalisers -- 6.7.4.Capacitive model of ungated and split-gated quantum Hall devices -- 6.7.5.Ungated quantum Hall devices -- 6.7.6.Split-gated quantum Hall devices -- 6.7.7.Double-shielded device -- References -- 7.1.General considerations -- 7.1.1.The causes of departure from an ideal transformer -- 7.1.2.The magnetic core -- 7.1.3.The windings; the effect of leakage inductances, capacitances and resistances -- 7.1.4.Representation of a non-ideal transformer: the effect of loading on its ratio windings -- 7.1.5.The two-stage principle -- 7.1.6.Electrical screens between windings -- 7.2.Constructional techniques -- 7.2.1.Design of transformer windings -- 7.2.2.Techniques for minimising the effect of leakage inductance, winding resistance and the capacitances of ratio windings -- 7.2.3.Bifilar winding -- 7.2.4.Rope winding having randomly arranged strands -- 7.2.5.Ordered rope winding -- 7.2.6.Magnetic and electric screens -- 7.2.7.Testing the attainment of a nearly toroidal field -- 7.2.8.Connections to the output ports -- 7.3.Types of transformers -- 7.3.1.Inductive voltage dividers -- 7.3.2.Two-staged IVDs -- 7.3.3.Injection and detection transformers -- 7.3.4.Use of an injection transformer as a small voltage source -- 7.3.5.Use of an injection transformer as a detector of zero current -- 7.3.6.Calibration of injection transformers and their associated phase change circuits -- 7.3.7.Voltage ratio transformers -- 7.3.8.Two-stage construction -- 7.3.9.Matching transformers -- 7.3.10.Current ratio transformers -- 7.3.11.High-frequency construction -- 7.4.Calibration of transformers -- 7.4.1.Calibrating an IVD in terms of a fixed-ratio transformer -- 7.4.2.Calibrating voltage ratio transformers using a calibration transformer with a single output voltage -- 7.4.3.Calibration with a 1:-1 ratio transformer -- 7.4.4.The bridge circuit and details of the shielding -- 7.4.5.The balancing procedure -- 7.4.6.Calibrating voltage transformers by permuting capacitors in a bridge -- 7.4.7.Calibration of current transformers -- 7.4.8.Assessing the effectiveness of current equalisers -- References -- 8.1.Designing bridge networks -- 8.1.1.Applying coaxial techniques to classical single-conductor bridges -- 8.1.2.Placement of current equalisers -- 8.1.3.Wagner circuit (and when it is applicable) -- 8.1.4.Convergence -- 8.1.5.Moving a detector to other ports in a bridge network -- 8.1.6.T-connecting shunt impedances for balance adjustment -- 8.1.7.Role of electronics in bridge design -- 8.1.8.Automating bridge networks -- 8.1.9.Higher-frequency networks -- 8.1.10.Tests of the accuracy of bridges -- References -- 9.1.Bridges to measure the ratio of like impedances -- 9.1.1.A two-terminal IVD bridge -- 9.1.2.A two-terminal-pair IVD bridge -- 9.1.3.A four-terminal-pair IVD bridge -- 9.1.4.A two-terminal-pair bridge based on a 10:-1 voltage ratio transformer -- 9.1.5.A four-terminal-pair bridge based on a two-stage 10:-1 voltage ratio transformer -- 9.1.6.Equal-power resistance bridge -- 9.2.Bridges to measure the ratio of unlike impedances -- 9.2.1.R-C: the quadrature bridge -- 9.2.2.The quadrature bridge-a two-terminal-pair design -- 9.2.3.The quadrature bridge-a four-terminal-pair design -- 9.2.4.Bridges for measuring inductance -- 9.3.AC measurement of quantum Hall resistance -- 9.3.1.AC contact resistance -- 9.3.2.AC longitudinal resistance -- 9.3.3.Measuring RxxLo -- 9.3.4.Measuring RxxHi -- 9.3.5.A simple coaxial bridge for measuring non-decade capacitances -- 9.3.6.Coaxial resistance ratio bridges involving quantum Hall devices -- 9.3.7.A quadrature bridge with two quantum Hall devices -- 9.4.High-frequency networks -- 9.4.1.An IVD-based bridge for comparing 10:1 ratios of impedance from 10 kHz to 1 MHz -- 9.4.2.A bridge for measuring impedance from 10 kHz to 1 MHz based on a 10:-1 voltage ratio transformer -- 9.4.3.Quasi-four-terminal-pair 1:1 and 10:1 ratio bridges for comparing similar impedances from 0.5 to 10 MHz -- 9.4.4.A four-terminal-pair 10-MHz 1:1 resistance ratio bridge -- 9.4.5.A 1.6- and 16-MHz quadrature bridge -- 9.4.6.Four-terminal-pair resonance frequency measurement of capacitors -- 9.4.7.Scattering parameter measurements and the link to microwave measurements -- 9.4.8.Electronic four-terminal-pair impedance-measuring instruments -- References -- 10.1.Resistance thermometry (DC and low-frequency AC) -- 10.1.1.DC resistance thermometry -- 10.1.2.AC resistance thermometry -- 10.2.Superconducting cryogenic current comparator -- and Contents note continued: 10.2.1.Determining the DC ratio of two resistances R1/R2 -- 10.3.Josephson voltage sources and accurate voltage measurement -- 10.4.Future directions -- 10.4.1.Higher-frequency measurements of quantum Hall resistance -- 10.4.2.Comparing calculable resistance standards up to 100 MHz with finite-element models -- 10.4.3.Radiofrequency and microwave measurements of carbon nanotubes and graphene -- References.
- The authors have between them more than 60 years of experience in making electrical measurements in National Measurement Laboratories. These laboratories are the source of measurement standards and techniques for science and engineering and are dedicated to maintaining the international system of unites (SI) by establishing and disseminating the values of measurement standards with the lowest possible uncertainty. Careful attention to detail is required in designing measurement systems that eliminate electrical interference and are as simple and as close to first principles as possible. This book draws on their experience by offering guidance and best practice for designing sensitive electrical measurement circuits. -- and In particular the book describes examples that demonstrate the elegance, flexibility and utility of balanced-current coaxial networks in obtaining the ultimate in noise-matching and interference elimination for precise and accurate voltage, current and power measurements. It also updates an earlier book on coaxial AC bridges by including recent AC measurements of quantum Hall resistance to establish a primary quantum standard of impedance and by extending impedance measurements in general to higher frequencies. --Book Jacket.
- 9781849190695 (pbk.) and 1849190690 (pbk.)
- Bibliography Note:
- Includes bibliographical references and index.
View MARC record | catkey: 7273058