The setting of alarm levels plays a vital role in a machinery condition monitoring and diagnostic system. In this research, two approaches to setting vibration alarm levels using vibration signals produced by fire pumps are presented in the time and frequency domains. In the time domain, the cross peak analysis (CPA) is proposed to extract the dominate peak points. The distribution of these cross peak points is found to have a lognormal distribution and can be normalized to a Normal...
Topics: 1/1 Octave Band Analysis, Alarm Level, Condition Monitoring and Diagnostics, Cross Peak Analysis,...
India’s cities are growing rapidly, resulting in wide variety of environmental stresses. Delhi’s current population is 18 million is growing rapidly. The results show that Delhi is developing very rapidly. The study shows that a 122 increase in highly dense area was recorded during last decade in Delhi. The pollution load has increased in terms of air, water, noise, and solid waste generation and disposal, etc. One of the many environmental problems faced is related to noise pollution. Many...
Topics: New Delhi, Pharganj-Moolchand, Noise pollution, Decibel, Sound level Metre, Octave band Analyzer,...
The construction sector provides occupational risks to construction workers at the building site. Despite the obligation of the use Individual Protection Equipment (IPE), the noise is one of the occupational risks, which persist as one of the most injury to workers. The causes may be inherent in the control, but also the inappropriate choice of the methods of implantation of hearing protectors as an individual control measure. This paper aims to analyze the efficiency of hearing protectors,...
Topics: Construction, occupational hazards, noise, octave band, PPE.
R&D Report 1995-07 : Further investigations of partitions having built-in acoustic treatment. G.D. Plumb Laboratory measurements were made of the sound insulations and absorption coefficients of a range of metal-framed partitions having built-in acoustic treatment. The partitions were made using glass wool and gypsum boards. The sound insulations of the single leaf partitions having built-in acoustic treatment were considerably lower than those of comparable partitions made using mineral...
Topics: partitions, mineral, partition, glass, insulations, unperforated, perforated, wool, absorption,...
R&D Report 1995-06 : Lightweight partitions having improved low frequency sound insulations. G.D. Plumb The sound insulations were measured of a range of single, double and triple leaf partitions. For the single leaf partitions, a staggered stud configuration was used. For the double and triple leaf partitions, the configuration of the boards was different from that in the conventional Camdens. At low frequencies, the partitions tested generally had higher sound insulations than comparable...
Topics: partition, insulations, sound, leaf, wool, triple, camden, partitions, insulation, double,...
R&D Report 1994-15 : The sound insulations of studio doors: Part 2: Door seals G.D. Plumb, R. Clark The acoustic performances of a range of proprietary acoustic door seals were measured in the Transmission Suite. The seals were fitted to a standard BBC lead-cored door hung in a purpose-built blockwork wall. As a result of the work, suitable plant-on magnetic perimeter seals and drop-down threshold seals are recommended. The use of these seals will simplify the existing door frame design and...
Topics: seals, threshold, perimeter, fitted, raven, insulations, magnetic, door, compression, bbc, octave...
R&D Report 1994-14 : The sound insulations of studio doors: Part 1: Door Blanks G.D. Plumb, R. Clark The sound insulations of a range of different door blanks were measured. The results were compared with the sound insulations of existing BBC door blanks. The new doors were made from medium density fibreboard (MDF) which is more stable than the blockboard used in existing studio doors. Consequently, they should require less maintenance and adjustment and should have a longer lifespan. The...
Topics: mdf, door, insulations, bitumen, damping, measured, bbc, sound, acoustic, lightweight, band centre,...
R&D Report 1994-12 : A wideband absorber for television studios. M.D.M. Baird The acoustic treatment in BBC television studios has taken various forms to date, all of which have been relatively expensive, some of which provide inadequate absorption. An investigation has been conducted into the possibilities of producing a new type of wideband absorber which, would be more economic, also taking installation time into account, than earlier designs. This Report describes the absorption...
Topics: absorption, absorber, wideband, frequency, acoustic, mineral, bbc, zintec, weldmesh, absorbers,...
R&D Report 1994-07 : Further measurements of the sound insulations of metal-framed partitions. G.D. Plumb The sound insulations were measured of a number of single and double leaf metal-framed partitions. The purpose of the work was to develop alternative designs for partitions to that of the Camden. The Camden contains fibreboard as one of its constituent elements. The new partitions used plasterboard as the sole board material. Therefore, the new partitions were heavier than the...
Topics: partition, partitions, insulations, plasterboard, wool, narrow, leaf, sound, camden, insulation,...
R&D Report 1994-06 : Acoustic noise criteria for listening rooms and control rooms R. Walker This report is based on a submission document to both EBU G1(LIST) and ITU-R TG 10/3 drafting committees. It describes background noise criteria for high-quality listening environments from a number of different organisations and the derivation of a compromise criterion for the continuous background noise levels. The outcome of the work, and the proposal submitted to those technical groups, was the...
Topics: noise, octave, curves, bbc, iso, oirt, rating, criteria, noise rating, curve, listening rooms, band...
R&D Report 1993-06 : Metal-framed partitions with reduced thicknesses: Part 2 -- Built-in acoustic treatment. G.D. Plumb Laboratory measurements were made of the sound insulations and absorption coefficients of a range of metal-framed partitions having built-in acoustic treatment. The optimum constructions for single and double leaf absorbent partitions had marginally lower sound insulations (approximately 1 dB) than those of comparable single and double metal-framed Camdens. The effective...
Topics: partitions, absorption, partition, sound, insulation, unperforated, perforated, leaf, acoustic,...
R&D Report 1993-05 : Metal-framed partitions with reduced thicknesses: Part 1 -- Narrower studs and cavities. G.D. Plumb The sound insulations were measured, in the Research Department Transmission Suite, of ten different metal-framed partitions. These partitions had narrower cavities and metal studs than those of the conventional thickness metal-framed Camden. Mineral wool had been installed in the cavities of some of the partitions and some partitions had double plasterboard skins rather...
Topics: sound, partitions, partition, studs, mineral, leaf, insulations, insulation, plasterboard, double,...
R&D Report 1992-09 : Low-frequency room responses: Part 2 -- Calculation methods and experimental results. R. Walker The development of a relatively simple method for predicting low- frequency responses for near-rectangular rooms based on the summation of modal responses and their coupling coefficients for the source and receiver positions is outlined. Comparisons between calculated and measured responses show that many of the response features can be reproduced. The question of optimum...
Topics: room, frequency, loudspeaker, frequencies, loudspeakers, octave, measured, mode, modes, response,...
R&D Report 1992-02 : On minimising noise problems caused by passenger lifts in studio centres. C.D. Mathers A number of passenger lifts have been investigated as sources of noise and vibration. Typical measured results are presented, and a number of problems and solutions are discussed. Finally, some general recommendations are listed, indicating how noise nuisance may be avoided or remedied.
Topics: pump, lift, vibration, hydraulic, ram, slab, lifts, noise, measurements, mounts, pump vibration,...
R&D Report 1989-02 : The control of the audible effects of ground vibrations in building structures. R. Walker, C.D. Mathers Over a period of about 8 years a number of investigations into the problems of vibration isolation, particularly of large structures, has been carried out, mostly in preparation for the development of a site (The Langham) which is subject to severe vibration interference from London Underground trains. The well-known limitations of some types of commercial vibration...
Topics: vibration, isolation, frequency, acoustic, studio, frequencies, measured, vibrations, resonant,...
R&D Report 1986-08 : The measurement of large values of airborne sound insulation. R.Walker The requirements for and the measurement of airborne sound insulation between areas in a broadcasting centre are discussed. In particular, the high values of insulation required in some cases and the difficulties of measurement are described. One method which has been used for such measurements, using explosive charges, has been investigated in detail. Some of the results obtained in the past using...
Topics: sound, measurement, insulation, signal, level, noise, frequency, pressure, overload, acoustic, peak...
R&D Report 1981-02 : An investigation into the spectral content of pop music. K.E. Randall In the design of a high-level studio monitoring loudspeaker, account must be taken of the type of programme that will be fed to it. When used to monitor pop music, which may contain relatively high levels of low frequencies, the maximum sound pressure level obtainable may be restricted by cone-movement limitations to a value which is unacceptably low for the studio manager to obtain the correct music...
Topics: loudspeaker, pop, music, spectra, sound, signal, levels, bbc, spectral, extract, octave band,...
R&D Report 1981-01 : Revision of the sound insulation requirements in broadcasting studio centres. R. Walker The BBC sound insulation requirements within studio centres have been based on a report published in 1968. Since that time, there have been new measurements of sound pressure levels in studios, control rooms and other areas, and new background noise level criteria have been proposed for programme areas. Both of these factors affect the amount of sound insulation which is necessary to...
Topics: insulation, sound, noise, studio, criteria, frequency, pressure, level, criterion, background,...
R&D Report 1980-08 : Revised background noise criteria for broadcasting studios. D.J. Meares, K.F.L. Lansdowne To achieve the correct working conditions in its studios, the BBC has, for many years, specified the maximum level of background noise that can be tolerated. This Report examines the 1968 noise criteria bearing in mind the performance of the current broadcasting network, and concludes that revisions are necessary. Based on a study of estimated and measured signal-to-acoustic noise...
Topics: noise, studio, studios, acoustic, criteria, sound, ventilation, bbc, criterion, drama, noise level,...
R&D Report 1966-29 : Consideration of aircraft noise and studio roof insulation A.N. Burd The increase of noise arising from the widespread use of jet aircraft has led to interference with programme in some broadcasting studios. The actual levels and spectra of noise from aircraft and the distribution of noise levels around a major airport are considered in order to reach a specification for the sound insulation of roofs to exclude such noise.
Topics: noise, levels, aircraft, roof, studio, octave, sound, insulation, spectra, pndb, pressure levels,...
R&D Report 1966-27 : Noise in studios from sonic booms. A.N. Burd, M.E.B. Moffat A brief description is given of the causes and some effects of sonic booms produced by supersonic aircraft. The results of measurements made during a demonstration of sonic booms have been used to show that studio roofs having an average insulation of 70 dB are probably adequate protection against sonic booms of intensities likely to be accepted in urban areas.
Topics: sonic, booms, boom, noise, sound, pressure, studio, aircraft, measurements, wave, rise time, ground...
BBC Monograph 73: Sonic Booms and Other Aircraft Noise in Studios. A.N. Burd, M.E.B. Moffat.
Topics: noise, sonic, aircraft, sound, bbc, studio, booms, levels, roof, insulation, pressure levels,...
