The object of frequency analysis is to break down a complex signal into its components at various frequencies, and it can be shown that this is possible for all practical signals. The word 'components' can be interpreted in several different ways, however, and it is important to clarify the differences between them.
The book "Mechanical Vibration and Shock Measurements” has long been a mainstay in Brüel & Kjær's series of books on the fundamentals of physical measurement and analysis. Although the basic theory is still valid, a great many developments have occurred since the book was last revised by Professor Jens Trampe Broch in May 1972, and it was decided in 19 7 9 to bring the book fully up-to-date, partly by a revision of existing material, and partly by adding new chapters where relevant. It was decided to keep as closely as possible to Professor Trampe Broch's original text, and he has had the opportunity to approve the modifications. Even so, it is probably as w ell to make it clear how much of the present book is taken from the original, and how much is completely new.
This booklet is intended as an introduction to the methods and instrumentation developed by Brüel & Kjær in the sphere of architectural acoustics. With this aim in mind the reader is presented with the basic theory necessary to make the best use of the instruments' capabilities
This booklet is adapted from a publication of the Swedish workers protection fund (Arbetarskyddsfonden) and is printed with the permission of the fund. Established by national legislation and funded via a small levy on the total wage bill, the fund is operated jointly by the employers and trade unions. Its object is to make industry and industrial employees aware of safety and environmental questions, and to encourage the provision of an improved and safer working environment throughout Swedish industry. To this end it conducts research and collates industrial experience on a number of different subjects, of which the effects and reduction of noise is one. The results of its work are then distributed to interested parties in a straightforward and understandable form for the benefit of the non-experts in individual factories who have to deal with the problems at first hand, as well as those with previous knowledge. It is hoped that this booklet will spread the benefits of this work to a wider audience than was originally possible.
The object of this publication is to give the prospectives train gauge user a simple explanation of the basic theory and practice of measurement using strain gauges. lt will show how various factors, such as type of gauge,gauge material, measuring conditions and type of instrumentation can influence the results obtained.
Recent years have seen the rise of vibration problems associated with structures which are more delicate and intricate, and machines which are faster and more complex. The problems have been coupled with demands for lower running costs and increased efficiency. Concern has also arisen about the effects of noise and vibration on people and on the working lifetime of manufactured items. Consequently, there has been a requirement for a greater understanding of the causes of vibration and the dynamic response of structures to vibratory forces. To gain such an understanding an accurate, reliable and versatile vibration transducer is required. In addition, advanced measurement and analysis equipment is often used. However, both the versatility and capability of such equipment would be wasted without an accurate vibration signal from a reliable vibration transducer.
Les annees recentes ont vu la multiplication des problemes de vibrations associes a des structures plus delicates et a des machines plus rapides et plus complexes. ces probldmes sont ll6s aux exigences du marchd pour un mellleur rapport qualit6/prix. une attention particuligre est aussi portee sur les effets du bruit et des vibrations sur les hommes, et sur la dur6e de vie des produits manufactures. ll s'lmpose donc une meilleure compr€henslon des causes de vibratlons et des reponses dynamiques des structures aux forces vibratoires. A cet eftet, un capteur de vibrations pr6cis, fiable et versatile est requis. De plus, les appareils de mesure et d'analyse trds sophistiques qui sont souvent utilises sont inutiles sans signaux de vibrations precis venant d'un capteur fiable.
The majority of the world’s major commercial airports, and a significant number of airport bases, have adopted processes and systems to manage the impact of operational noise from the airport onto surrounding communities.
This handbook contains specific information about Brüel & Kjær’s Falcon™ Range of 1/2" microphone products. It contains a chapter on each of the microphones, a chapter on 1/2" Microphone Preamplifier Type 2669 which can be used with these microphones, and a list of the available accessories which can also be used with these microphones.
The B&K measurement microphones are designed for accurate sound measuring purposes. They are precision engineered from materials selected to give long term stability. Their resistance to humidity is very high, the temperature range very wide and the temperature coefficient extremely small compared to other types of condenser microphones. A robust construction makes them easy to handle in the field. Each microphone is delivered in a protective mahogany box supplied with an individual calibration chart giving the frequency response and all data necessary for precision measurements.
On voudra bien n’entendre ici, par Bruit de l’environnement, que les nuisances sonores induites par les activités industrielles, de transport terrestre et aérien, et les activités à caractère sportif, commercial ou culturel organisées dans les édifices et lieux publics. Ce terme n’englobe pas les applications apparentées, relatives notamment à l’acoustique du bâtiment ou aux nuisances dues aux vibrations, ni même le bruit de voisinage. Ne sont abordés dans ces pages ni l’effet et le mesurage des vibrations sur le corps humain ni les applications industrielles de la mesure vibroacoustique. Brüel&Kjær se tient à votre disposition pour toute question concernant ces domaines spécifiques.
Diese Broschüre beschäftigt sich mit Umweltlärm − zum Beispiel Lärm von Industrieanlagen, Straßen- und Schienenverkehr, Flughäfen und Vergnügungsparks. Nicht behandelt werden verwandte Gebiete wie Bauakustik, Schwingungen an Gebäuden und im Wohnbereich erzeugter Lärm. Ebenfalls nicht behandelt werden Wirkungen von Schwingungen auf den Menschen sowie industrielle Anwendungen von Schall- und Schwingungsmessungen. Bitte wenden Sie sich an Ihr Brüel&Kjær Verkaufsbüro, wenn Sie weitere Informationen zu diesen Themen brauchen.
Este documento trata del ruido ambiental – por ejemplo, ruido procedente de polígonos industriales, carreteras y ferrocarriles, aeropuertos y parques de atracciones. No cubre temas relacionados con éstos tales como la acústica de edificios, las vibraciones en edificios o el ruido doméstico. Tampoco cubre la respuesta humana a la vibración ni a los usos industriales de las mediciones de sonido y de vibración. En caso necesario contacte con su representante de Brüel & Kjær para recibir más información con respecto a estos temas.
Questo opuscolo descrive le varie forme di rumore ambientale/inquinamento acustico a cui siamo soggetti − per esempio rumore proveniente da aree industriali, da traffico stradale e ferroviario, da aeroporti e complessi commerciali, ma non ricopre quegli argomenti in correlazione come l’acustica architettonica, le vibrazioni nei fabbricati ed il rumore domestico e neanche ciò che riguarda la risposta umana alle vibrazioni e gli usi industriali delle misure acustiche e delle vibrazioni. Per ricevere informazioni più approfondite riguardo queste materie, vi preghiamo di contattare il Vostro rappresentate locale Brüel&Kjær. Anche se non si può garantire un’informazione totale di tutti gli aspetti, si è cercato di presentare in questo opuscolo una panoramica aggiornata di tutte le normative, raccomandazioni, regolamenti e metodi relativi all’inquinamento acustico. Per ottenere informazioni più dettagliate e pertinenti al Vostro Stato, Regione o Comune, Vi consigliamo di consultare le autorità locali in materia.
This booklet deals with environmental noise − for example, noise from industrial sites, road and rail traffic, airports and fairgrounds. It does not cover related issues such as building acoustics, building vibration or domestic noise.
This handbook gives an insight into the theory behind the development of microphones and preamplifiers and explains the terminology used to describe these products. The aim of this volume is to promote a full understanding of measurement microphones and to provide sufficient background information for customers to get the best out of these products. It also gives adequate information for customers to be able to make informed and qualified decisions about the microphone products which are most suitable for their measurement requirements.
This handbook contains specific information about Brüel & Kjær's Falcon™ Range of 1/2" microphone products. It contains a chapter on each of the microphones, a chapter on 1/2" Microphone Preamplifier Type 2669 which can be used with these microphones, and a list of the available accessories which can also be used with these microphones.
This booklet gives an introduction to the design features and operating principles of measuring microphones. Some knowledge about the measurement of sound would be an advantage and so you might wish to consult our companion booklets "Measuring Sound" and "Sound Intensity".
This booklet sets out to explain the fundamentals of sound intensity measurement. Both theory and applications will be covered. Although the booklet is intended as a basic introduction, some knowledge of sound pressure measurement is assumed. If you are unfamiliar with this subject, you may wish to consult our companion booklet "Measuring Sound".
This booklet answers many of the basic questions about occupational noise exposure and hearing conservation.
This booklet is an introduction to human vibration. It explains what is meant by human vibration; why we are, or should be, interested in human vibration; how it is measured and what action can be taken to reduce human exposure to vibration.
Modal analysis is an efficient tool for describing, understanding, and modeling structural behaviour. The study of modal analysis is an excellent means of attaining a solid understanding of structural dynamics. "Structural Testing" consists of a comprehensive introduction to the theoretical background to modal analysis and structural dynamics.
Modal analysis of the data obtained from structural testing, provides us with a definitive description of the response of a structure, which can be evaluated against design specifications. It also enables us to construct a powerful tool, the modal model, with which we can investigate the effects of structural modifications, or predict how the structure will perform under changed operating conditions.
The influence of acoustics on the design of buildings can be observed through the ages from Roman amphitheatres to the modern houses or buildings in which we spend our working hours and our leisure. The great difference, however, between life in ancient Rome and life in our crowded modern cities is the presence of noise from an ever increasing number of sources, from neighbours, traffic and industry.
This booklet answers many of the basic questions about environmental noise criteria and environmental noise measurements.
This booklet gives answers to some of the basic questions asked by the newcomer to a noise measuring programme. It gives a brief explanation to questions like: What is sound ? Why do we measure sound ? What units do we use ? How do we hear ? What instruments do we use for measurement ? What is a weighting network ? What is frequency analysis ?
This booklet gives an introduction to the methods used in vibration testing and a description of the vibration exciters and control equipment used in environmental testing and in determination of dynamic properties of structures.
This booklet answers some of the basic questions asked by the newcomer to vibration measurement. It gives a brief explanation to the following: Why do we measure vibration? Where does it come from? What is vibration? How to quantify the vibration level, The vibration parameters, Acceleration, Velocity and Displacement, Measurement Units, Which parameter to measure, The piezoelectric accelerometer