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Electrical Instruments / Elektrische Instrumente PDF

544 Pages·1967·11.249 MB·English-German
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ENCYCLOPEDIA OF PHYSICS CHIEF EDITOR S. FLOGGE VOLUME XXIII ELECTRICAL INSTRUMENTS EDITOR A. E. PANNENBORG WITH 391 FIGURES S P R IN G E R -V E R LA G BERLIN· HEIDELBERG· NEW YORK 1967 HANDBUCH DER PHYSIK HERAUSGEGEBEN VON S. FLOGGE BAND XXIII ELEKTRISCHE INSTRUMENTE BANDHERA U SGEBER A. E. PANNENBORG MIT 391 FIG U REN S P R IN G E R -V E R LA G BERLIN· HEIDELBERG· NEW YORK 1967 Alle Rech te, insbesondere das der Dbersetzung in frernde Sprachen, vorbehalten Ohne ausdriickliche Genehrnigung des Verlages ist es auch nicht gestattet, dieses Buch oder Teile daraus auf photomechanischem Wege (Photokopie, Mikrokopie) oder auf andere Art Zli vervieWiltigen ISBN-13: 978-3-642-46073-9 e-ISBN-13: 978-3-642-46071-5 DOl: 10.1007/978-3-642-46071-5 © by Springer-Verlag Berlin· Heidelberg 1967 50ftcover reprint of the hardcover I 5t edition 1967 Library of Congress Catalog Card Number A56-2942 Die Wiedergabe von Gebrauchsnamen, Handelsnamen, Warenbezeichnungen usw. in diesern Werk berechtigt auch ohue besondere Kennzeichnung nicht Zli der Annahme, daB solche Narnen im Siun der Warenzeichen- und Markenschutz Gesetzgebung als frei zu betrachten waren und daher von jedennann benutzt werden diirften Titel-Nr. 5761 Inhaltsverzeichnis. Seite Low Noise Amplification. By MICHIYUKI UENOHARA, Bell Telephone Labs, Inc. Murray Hill, New Jersey, USA. (With 71 Figures) .. I. Introduction. . . . . . . . . . . . . . . . 1 II. Noise factor, noise temperature and noise measure 3 III. Measurement of low noise temperature 7 IV. Grid control tube and transistor amplifiers. 18 V. Low-noise traveling-wave tube amplifiers 31 VI. Parametric amplifiers . 37 VII. Tunnel diode amplifier 67 VIII. Conclusion. . . . . . 81 Measurement Methods and Instruments for Microwave Frequencies. By Dr. ARTHUR F. HARVEY, Royal Radar Establishment, Malvern (Great Britain). (With 79 Figures) 84 List of symbols . . . . . . . . 84 I. General principles . . . . . 85 a) Electromagnetic radiation 85 b) Radiation and matter . 88 c) Circuits and components 90 II. Basic electrical quantities . 95 a) Measurement of power. 95 b) Measurement of attenuation 106 c) Measurement of impedance 113 III. Wavelength. . . . . . . . 120 a) Transmission-line methods 120 b) Free-space methods . . 126 IV. Properties of materials . . . 131 a) Dielectric measurements . 131 b) Molecular spectra of gases 141 c) Magnetic-field effects 146 d) Time-dependent phenomena 156 V. Frequency ..... 162 a) Direct measurement . 162 b) Reference standards . 166 VI. Miscellaneous techniques 172 a) Noise measurements. 172 b) Electromagnetic field strength 179 c) Relativity and gravitation 182 References . . . . . . . . . . . . . 185 Messung von Magnetfeldern. Von Dr. phil. nat. HERBERT WEISS, Siemens-Schuckert- Werke/AG., Forschungslaboratorium Erlangen. (Mit 18 Figuren) 198 Einleitung. . . . . . . . . . . . . . . . . . . . . . . . 198 1. Resonanzmethoden . . . . . . . . . . . . . . . . . . 198 2. Nichtlinearitat der B-H-Kurve ferromagnetischer Materialien 203 3. Induktionsspulen . . . . . . . . . . . 206 4. Galvanomagnetische Effekte in Halbleitern 207 5. Sonstige Methoden. 214 Literatur. . . . . . . . . . . . . . . . . 215 VI Inhaltsverzeichnis. Seite Recording of Measuring Data. By Prof. Dr. Ir. CORNELIS J .D.M. VERHAGEN, Professor Technological University, Delft (Netherlands) and Ir. JURRIAN FREDERIC VAN TOL, Member of the Scientific staff, Technological University Delft (Netherlands). (With 40 Figures) . . . . . . . . . . 217 A. Analogue and digital recording 217 B. Means of recording . . . . . 222 C. Analogue recording methods . 230 I. Continuously recording systems . 230 a) Optical recording . . . . 230 aa) Light beam oscillographs. . 231 ab) Cathode ray oscilloscopes. . 238 b) Direct acting and indirect acting recording 249 ba) Direct acting recorders. 249 bb) Indirect acting systems. . . . 251 c) Magnetic recording . . . . . 258 II. Discontinuously recording systems 261 III. Intermittently recording systems . 271 D. Digital recording methods . . . . . . 273 E. Standard recording equipment for a laboratory and outlook. 284 Literature . . . . . . . . . . . . . . . . . . . . . . . . 287 Frequency and Time Measurements. By ALAN BAGLEY, Frequency and Time Division of Hewlett-Packard Corp. Palo Alto, California (United States of America). (With 65 Figures) 289 A. Introduction . . . . . . . . . 289 B. Time and frequency references. 290 I. Time definitions. . . . . 290 II. Epoch and time interval . 292 III. Standard frequency and time signal broadcasts 292 IV. Time synchronization 299 V. Accuracy and stability . 301 a) Accuracy . . . . . 301 b) Long-term stability . 302 c) Short-term stability. 306 d) Factors affecting long-term and short-term stability. 314 VI. Time and .frequency standards 315 a) General . . . . . . . . . 315 b) Quartz frequency standards 317 c) Atomic frequency standards 321 C. Frequency measuring instruments and techniques 328 I. Introduction . . . . . 328 II. Frequency counters . . 329 III. Wavemeters and bridges 342 IV. Ratemeters. . . . . . 345 V. Heterodyne frequency meters 348 VI. Oscilloscope comparisons . . 349 VII. Frequency synthesizers. . . 350 VIII. Mixing, multiplying, and dividing 353 IX. Measurements on resonant systems. 357 D. Time interval measurements 360 I. General ..... . 360 II. Counters . . . . . . 360 III. Other methods of time interval measurement 367 References ................. . 371 Inhaltsverzeichnis. VII Seite Temperaturmessung. Von Dipl.-Ing. WALTER HUNSINGER, Hartmann & Braun AG, Frankfurt a. M. (Mit 40 Figuren) . . . . . . 373 A. Temperaturskala und Thermometerarten. . . . 373 I. Thermodynamische Temperaturskala 373 II. Internationale Praktische Temperaturskala 374 III. Thermometerarten und Begriffe der Thermometrie 378 B. Elektrische Beriihrungsthermometer . 380 I. Thermoelemente . . . . . 380 a) MeBprinzip ..... 380 b) Arten von Thermopaaren 381 c) Aufbau und Ausfiihrung von Thermoelementen. 385 d) Ausgleichsleitungen. . . . . . . . . . . . . 388 e) Konstanthaltung der Vergleichstemperatur 390 f) Rechnerische Beriicksichtigung der Vergleichstemperatur 390 g) Selbsttatige Beriicksichtigung der Vergleichstemperatur 392 II. Widerstandsthermometer mit metallischen MeBfiihlern . 393 a) MeBprinzip und Werkstoffe 393 b) Aufbau und Ausfiihrung 395 c) Erwarmungsfehler . . . . . . . 396 d) EinfluB des Zuleitungswiderstands 397 III. Widerstandsthermometer mit Halbleiter-MeBfiihlern . 399 a) MeBprinzip und Werkstoffe . 399 b) Ausfiihrung und Anwendung ......... . 400 IV. Quarzthermometer . . . . . . . . . . . . . . . 401 C. Verfahren und Gerate zur Thermospannungs- und Widerstandsmessung 402 I. Messung der Thermospannung 402 a) Ausschlagsverfahren 402 b) Kompensationsverfahren 408 c) MeBverstarker . . . . 416 II. Messung des Widerstands 419 a) Quotienteninstrumente 419 b) Unvollstandig abgeglichene Briicken 420 c) Abgeglichene Briicken. . . . 423 d) Kompensatoren ...... . 424 D. Einbau von Beriihrungsthermometern . 425 I. Messung im Inneren fester IG:irper. 425 II. Messung an der OberfHiche fester Kiirper . 426 a) An ruhenden Oberflachen 426 b) An bewegten Oberflachen 427 III. Messung in Fliissigkeiten. . 428 IV. Messung in Gasen. . . . . 428 a) Berechnung des Warmeleitungsfehlers . 428 b) Bestimmung des Warmeleitungsfehlers aus Thermometerkennzahlen 431 c) Hinweise zum Kleinhalten des Warmeleitungsfehlers . . . . . " 433 E. Zeitverhalten von Thermometern . . . . . . . . . . . . . . . . . . . 434 I. Anzeigeverziigerung bei einmaliger pliitzlicher Temperaturanderung COber gangsfunktion) . . . . . . . . . . . . . . . . . . . . 435 II. Anzeigeverziigerung bei zeitabhangiger Temperaturanderung 440 F. Strahlungspyrometer . . . . . . . . . 441 I. Strahlungsgesetze. . . . . . . . . . . . . . . . . 441 II. Einteilung der Strahlungspyrometer. . . . . . . . . 444 a) Kennzeichnung nach der Art der Strahlungsmessung 444 b) Kennzeichnung nach charakteristischen Pyrometerbauteilen 446 III. Ausfiihrung von Strahlungspyrometern . . . . . . 446 a) Gesamtstrahlungs- und Bandstrahlungspyrometer 446 b) Spektralpyrometer . . . . . . . 450 c) Vertcilungspyrometer ..... . 453 IV. Verhalten von Strahlungspyrometern 454 Literatur 455 VIII Inhaltsverzeichnis. Seite Temperaturregelung. Von Dipl.-Ing. FRITZ SCHREINER, Hartmann & Braun AG, 6 Frankfurt a. M. (Mit 78 Figuren) 457 A. Begriffe und Benennungen 457 I. Regelung. . 457 II. Steuerung . . 459 B. Die Regeistrecke . 459 I. Methoden zur Ennittiung und Beschreibung des Signaitibertragungsver- haltens . . . . . 459 a) Statisches Verhalten . . 460 b) Dynamisches Verhalten . 461 c) Die Differentiaigieichung 465 II. Beispiele flir Temperaturregeistrecken 469 a) Dampfbeheiztes ReaktionsgefaB . 469 b) Erfahrungswerte ftir Temperaturregelstrecken 471 C. Der lineare RegIer. . . . . . . . . . . 471 I. Die Grundtypen der linearenRegler . . . . . . 471 a) Der Proportionairegier (P-RegIer). . . . . . 472 b) Der Proportionairegier mit Differentialanteil (PD-Regler) 473 c) Der Integrairegier . . . . . . . . . . . . . . . . . 474 d) Proportional-Integral-Regler (pI-RegIer) . . . . . . . 474 e) Der Proportional-Integral-Regler mit Differentialanteil (pID-RegIer) 475 II. Geratetechnische Ausftihrung linearer RegIer. . . 475 a) Prinzip der Rtickflihrung . . . . . . . . . . 475 b) Dbersicht tiber die gebrauchlichen Regiertypen. 477 D. Der lineare Regeikreis . . . . . . . . . . 479 1. SchlieBungsbedingung und Gieichungen 479 II. Stabilitatsuntersuchungen . . . . . . 480 a) Allgemeines . . . . . . . . . . . 480 b) Stabilitatsprtifung mit der Differentiaigieichung nach ROUTH-HuRWITZ 481 c) Stabilitatsprlifung mit der Frequenzgangdarstellung 482 III. Einstellung von linearen Regeikreisen 483 a) Aligemeines . . . . . . 483 b) Regelflachenkriterien . . . . . 485 c) Einstellwerte flir RegIer. . . . 486 E. Regelkreise mit nichtlinearen Gliedern . 488 I. Der Zweipunktregler. . . . . . . 488 a) Die Kenniinie des Zweipunktregiers . 488 b) Zweipunktregier an einer Regelstrecke 1. Ordnung mit Totzeit 489 c) Zweipunktregier mit Rtickflihrung . . . . . . . . 493 d) Geratetechnische Ausflihrung von Zweipunktregiern 494 II. Der Dreipunktregier. . . . . . . . . . . . . . . . 500 a) Blockschaltbild und Zeitverhalten . . . . . . . . 500 b) Besondere Stabilitatsprobleme. . . . . . . . . . 501 c) Geratetechnische Ausflihrung von Dreipunktregiern. 502 III. EinfluB der Stellgliedhysterese auf Stabilitat und Regeigtite 503 F. Beispiele flir Temperaturregelungen . . . . . . . . . . 506 I. Einfache Temperaturregelungen ............ . 506 a) Regelung eines dampfbeheizten ReaktionsgefaBes. . . . 506 b) Zweipunktregelung eines elektrisch beheizten Laborofens 508 c) Dreipunktregelung eines elektrisch beheizten Ofe ns . . . 511 d) Regelung gas-oder oibeheizter Temperaturregeistrecken . 512 II. Vermaschte Temperaturregeikreise . . . . . . . 514 a) Arten der Vermaschung .......... . 514 b) Vermaschungen zur Verbesserung der Regeigtite 515 c) Mehrfachregelung. 518 Symbolliste . . . . . . . . . . . 520 Literatur ........... . 521 Sachverzeichnis (Deutsch-Englisch) . 522 Subject Index (English-German) .. 529 Low Noise Amplification. By M. UENOHARA. With 71 Figures. I. Introduction. Much of the recent progress in our understanding of the world around us was achieved through the ability to detect very weak signals, for example from outer space, from nerve fibers, or from the ocean floor. To detect these weak signals, one requires very sensitive receivers, and hence the ability to amplify these signals without, at the same time, introducing any appreciable amount of noise. In the microwave frequency range, this need was especially acute, in particular for radio astronomy, satellite communications and long range radars. This need was met by the improvement of well established amplifiers such as the traveling wave tube, the invention of new ones, such as the maser, and the realization of low noise parametric amplifiers. In the study of weak signals, undesirable natural and man-made noise always becomes associated with the desired signals. Additional noise is added to signal by the receiver (including detectors and energy converters), and this noise may mask weak signals which would still have been intelligible if the receiver were noiseless. Some forms of noise can, at least to some extent, be separated from the desired signal; however, thermal noise, shot noise and 1/1 noise, which are generated in most electron devices and are all random, stationary functions of time, appear to have fundamental lower limits. Noise - spontaneous fluctuations or emission of energy - is defined in the International Dictionary of Physics and Electronics as "Any undesired sound. By extension, noise is any unwanted disturbance within a useful frequency band, such as undesired electric waves in any transmission channel or device. Such disturbances when produced by other services are called interference." The noise sources in amplifiers include one or more of the following: 1. Thermal noise (Johnson noise). This is the noise caused by thermal agitation in a dissipative body, and is directly proportional to temperature. 2. Shot noise. The fluctuation in the current of charge carriers passing through a surface at statistically independent times. 3. Flicker noise. The large amount of noise over and above shot noise at low frequencies. This is often called 1/1 noise, because the noise spectrum is usually of the form t" with ~ close to unity. 4. Other excess noise. For example: a) In semiconductor devices a large amount of noise is generated near or at the avalanche breakdown voltage. b) In grid control tubes, induced grid noise, partition noise, secondary emission noise, ion noise, and primary emission noise from the control grid are significant sources of excess noise. Handbuch der Physik, Ed. XXIII. 2 M. UENOHARA: Low Noise Amplification. Except for the maser and parametric amplifier, shot noise is generally the dominant noise source in low noise amplifiers. In the parametric amplifier, thermal noise, especially that generated in the idler circuit, is the dominant one. At extremely low frequencies, however, flicker noise generally becomes the domi nant factor; for this reason, the signal is often first shifted by a low noise converter to a sufficiently high frequency, where flicker, noise is negligible, before it is amplified. There is still another class of noise generated in nonlinear amplifiers. This is often called coherent noise; crossmodulation and intermodulation signals belong in this category. Since most low noise amplifiers are low power devices, this 800.--.-.----,----.----,----.----,----,----,--,rnr---,---, SOO~~H----4----+---_+----r---~--~----+I_-'-: ~ ----hr--~ rJrici-collll'O/lvoe ~oo'e ITt/nne/ ~~OOI----~----_+-----+----_r----~----T_----T---~~~~~--~Hr--~ ~ ii! [JOO~--~---+--~~--+---~--~----+---~~~----~--~ ~ '<::: .~200~--~~r--+-----+-----r----~----+-----+-----r-T--+--~~----~ ~ /00 r---+-----'l.-I+-- __ __ O~~_L ~_~ _L_ _L __~ ___~ _~~~~~~~ ___ J Ie loe I/(e lOX /ooCC' Fig. 1. Lowest noise temperatures of amplifiers from subaudio frequency to microwave frequency, class of noise may be of concern if they are improperly operated at high signal levels. However, for most applications, the signal level is sufficiently low that this class of noise is not important, and we shall consider it no further. Low noise amplifiers have been especially intensively studied at microwave frequencies, since there the sky noise temperature is relatively low. The maser, low noise traveling-wave tube, and tunnel diode amplifier are practically limited to microwave applications. The parametric amplifier, on the other hand, can be operated as a very low noise amplifier from subaudio frequencies to microwave frequencies. In the intermediate frequency range, grid-control tubes and transistors are widely used. Fig. 1 shows the lowest noise temperatures practically obtainable from these amplifiers. Division 2 contains a definition of the parameters which characterize the nois iness of amplifiers. The noise factor (noise figure) is one of the parameters and has been in use for a long time. More recently an "effective input noise temperature" has gained increased usage for low-noise amplifiers. For practical applications, the low noise characteristic of an entire system is more important than that of the component amplifiers. The "operating noise temperature" is, therefore, a more useful parameter for system characterization. When many amplifiers are connected in cascade, the over-all system noise temperature is not only a function of the noise factors of cascaded amplifiers but also of the gains. The" noise meas- Sect. 1. Noise factor. 3 ure" includes both the noise factor and the gain and defines the ultimate noise characteristic of the amplifier in systems. In Division 3 the measurement of noise factor and noise temperature will be described. The accurate measurement of a low noise temperature is an extremely difficult task. Great care must be exercised to calibrate every component in the test set. Various kinds of noise generators as the noise references will be described and possible sources of measurement errors will be discussed. In the rest of the chapter, noise characteristics of the control-grid tube ampli fier, transistor amplifier, traveling-wave tube amplifier, parametric amplifier, and tunnel-diode amplifier will be discussed and some practical examples will be presented. Detailed theoretical derivations will be left to references and only important formulae will be presented. Since the maser is discussed elsewhere in the Encyclo-· pedia, the maser will not be covered in this chapter. II. Noise factor, noise temperature and noise measure. 1. Noise factor. The amplifier whose noise performance is under consideration here is essentially the linear two-port device. Signals enter the amplifier at the input port, are amplified internally, and leave the device at its output port. Any noise input accompanying the signal is also amplified in an identical manner. Noise generated in the amplifier is an additional noise at the output port that is independent of the signal and noise input. One measure of the noise performance of the amplifier is the noise factor (noise figure). The noise factor of linear noisy amplifier, at a specified input frequency, is defined1,2 as the ratio of 1) the total noise power per unit bandwidth at a cor responding output frequency available at the output port when the noise tempera ture of the input termination is standard (290° K) at all frequencies to 2) that portion of 1) engendered at the input frequency by the input termination. The noise factor depends upon the internal noise sources and structure of the amplifier, but not upon its output termination impedance. Thus F= No = !!s+Na =1 +!!"-- (1.1 ) Ns ~ ~ where No is the noise output of the amplifier when the input termination is at 290° K, Ns is the output noise component which owes its origin to thermal noise in the input termination at 2900 K, and Na is that produced by noise sources internal to the amplifier. IX) Average noise factor. In any system the signal is distributed over some finite bandwidth over which both signal and noise time averages may vary with fre quency. Since the amplifier is assumed to be linear, the noisiness of the amplifier can be defined by considering the total powers of signal and noise. The average noise factor is one such measure of noise performance. The average noise factor is defined 1,2 as the ratio of 1) the total noise power delivered by the transducer into the output termination when the noise temperature of the input termination is standard (290° K) at all frequencies to 2) that portion of 1) engendered by the input termination. For heterodyne systems (and others which associate with frequency conversion, e.g. a parametric amplifier), 2) includes only that portion of the noise from the input termination which appears in the output via the principal-frequency transformation of the system, and does not include any 1 IRE Standard 57 IRE 7. S 2: Proc. IRE 45,1000 (1957). 2 IRE Standard 59 IRE 20. S 1 : Proc. IRE 48, 61 (1960). 1 *

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