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IS 1890-7 (1995): Quantities and Units, Part 7: Acoustics [MSD 10: Social Responsibility]

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IS 1890-7 (1995): Quantities and Units, Part 7: Acoustics [MSD 10: Social Responsibility] इंटरनेट मानक Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. “जान का अधकार, जी का अधकार” “परा को छोड न 5 तरफ” Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru “The Right to Information, The Right to Live” “Step Out From the Old to the New” IS 1890-7 (1995): Quantities and Units, Part 7: Acoustics [MSD 10: Social Responsibility] “ान $ एक न भारत का नमण” Satyanarayan Gangaram Pitroda “Invent a New India Using Knowledge” “ान एक ऐसा खजाना > जो कभी चराया नह जा सकताह ै”ै Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 1890 (Part 7) : 1995 IS0 31-7 : 1992 *m m*FfJFf &7 wTR?a (mg;TfteToT1 Indian Standard QUANT-ITIES AND UNITS PART 7 ACOUSTICS ( First Revision ) UDC 53: 081 @ BIS 1995 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 September 1995 Price Group 6 Basic Standards Sectional Committee, MSD 1 NATIONAL FOREWORD This Indian Standard (Part 7) (First Revision) which is identical with IS0 31-7 : 1992, issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Basic Standards Sectional Committee (MSD 1) and approval of the Management and Systems Division Council. The text of the IS0 Standard has been approved as suitable for publication as Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian Standards. AtteJntion is particularly drawn to the following : Comma (J has been used as a decimal inarker while in Indian Standards the current practice is to use a point (.) as the decimal marker. Wherever the words ‘International Standard’ appear, referring to this standard, they should be read as ‘Indian Standard’. This standard was first published in 1983. In this revision, following changes have been made: a) The decision by the International Committee for Weights and Measures (CIPM) in 1980 concerning the status of supplementary units has been incorporated; b) The special remark on logarithmic quantities and units has been elaborated; and c) The annex on CGS units has been deleted. ADDITIONAL INFORMATION IS 189O/ISO~31 consists of the following parts, under the general title ‘Quantities and Units’: International Corresponding Indian Degree of Standard Standard Equivalence ISO~31_0 : 1992 IS 1890 (Part 0) : 1995 Quantities and units : Part 0 Identical General principles (first revision) IS0 31-1 : 1992 IS 1890 (Part 1) : 1995 Quantities and units : Part 1 Space Identical and time (third revision) IS0 31-2 : 1992 IS 1890 (Part 2) : 1995 Quantities and units : Part 2 Identical Periodic and related phenomena (second revision) IS0 31-3 : 1992 IS 1890 (Part 3) : 1995 Quantities and units : Part 3 Identical Mechanics (second revision) IS0 31-4 : 1992 IS 1890 (Part 4) : 1982* Quantities, units and symbols Technically Part 4 Heat (first revision) Equivalent IS0 31-5 : 1992 IS 1890 (Part 5) : 1995 Quantities land units : Part 5 Identical Electricity and magnetism (first revision) IS0 31-6 : 1992 IS 1890 (Part 6) : 1993* Quantities, units and symbols : Technically Part 6 Light and related electromagnetic radiations Equivalent IS0 31-7 : 1992 IS 1890 (Part 7) : 1995 Quantities and units : Part 7 Identical Acoustics (first revision) IS0 31-8 : 1992 IS 1890 -(Part 8) : 1995 -Quantities and units : Part 8 Identical Physical chemistry and molecular physics (first revision) IS0 31-9 : 1992 IS 1890 (Part 9) : 1995 Quantities and units : Part 9 Atomic Identical and nuclear physics (first revision) (Continued on third cover) IS 1890 (Part 7) : 1995 IS0 31-7: 1992 hdian Standard QUANTITIES AND UNITS PART 7 ACOUSTICS ( First Revision ) 1 Scope maintain registers of currently valid International Standards. This part of IS0 31 gives names and symbols for quantities and units of acoustics. Where appropriate, IS0 16: 1975, Acoustics - Standard tuning frequency conversion factors are also given. (Standard musical pitch). IS0 31-2:1992, Quantities and units - fart 2: Per- 2 Normative references iodic and related phenomena. The following standards contain provisions which, IS0 131 :I 979, Acoustics - Expression of physical through reference in this text, constitute provisions and subjective magnitudes of sound or noise in air. of this part of IS0 31. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this 3 Names and symbols part of IS0 31 are encouraged to investigate the possibility of applying the most recent editions of the The names and symbols for quantities and units of standards indicated below. Members of IEC and IS0 acoustics are given on the following pages. IS 1890 (Part 7) : 1995 IS0 31-7 : 1992 \COUSTICS Quantities Item Quantity Symbol Definition Remarks MO. '-1 period, T Time of one cycle periodic time ‘-2 frequency Jv f= l/T For the standard tuning fre- quency (standard musical pitch), see IS0 16. ‘-3 frequency interval For two tones, the~binary log- arithm of the ratio of the higher frequency to the lower fre- quency ‘-4 angular frequency, w 0 = 27cf pulsatance 7-5 wavelength 1 Distance in the direction of propagation of a periodic wave between two successive points where at a given time the phase is the same 7-6 repetency, u a-l/A The vector quantities u and k 4 wavenumber corresponding to repetency ant angular repetency are called wave vector and propagation vector respectively. 7-7 angular repetency, k k = 2~ j 7-6.7) angular wavenumber 7-8 volumic mass, e Mass divided by volume (7-7. 7) mass density, density 2 IS 1890 (Part 7) : 1995 IS0 31-7: 1992 Jnits ACOUSTICS International Item Name of unit symbol for Definition Conversion factors and remarks No. unit 7'-1 .a second S 7‘-2.a hertz Hz 1 Hz= 1 s-' 1 Hz is the frequency of a periodic phenomenon of which the period is 1 s. q_________ _________ -------_----------- --_ r-3.a octave The frequency interval The numerical value of the frequency between& andf, is one interval in octaves is given by octave if &/fi = 2 Ib(f,fiL ct; 2 A>. Ma radian per second rad/s -1 7-4.b reciprocal S second, second to the power minus one 7-5.a metre m 7-6.a reciprocal metre, m-’ metre to the power minus one -- 7-7.a radian per metre rad/m 7-7.b reciprocal metre, m-’ metre to the power minus one 7-8.a kilogram per kg/m3 cubic metre 3 IS 1890 (Part7) : 1995 IS0 31-7-z 1992 rcACOUSTICS (continued) Quantities item Quantity Symbol Definition Remarks No. 7.-9.1 static pressure Ps Pressure that would exist in the (; 7-8.1) 3 absence of sound waves 7,-9.2 (instantaneous) Pt (p,) Difference between the instan- When any of the quantities i; 7-8.2) sound pressure taneous total pressure and the 7-9.2 to 7-13 inclusive is per- static pressure iodic, its symbol is often used without modification for its 7.-10 (instantaneous) rt (XI Instantaneous displacement of root-mean-square (r.m.s.1 value. t; “9. I) sound particle a particle in a medium from displacement what would be its position in the absence of sound waves 7 -11 (instantaneous) u. v at t;7-10. I) sound particle U=at velocity au 7 -12 (instantaneous) a a=at (;7-l 1. I) sound particle acceleration 7 ‘-13 (instantaneous) Q, u, (4v) Instantaneous rate of volume ( 7-12. I) volume flow rate flow due to a sound wave w 7‘-14.1 velocity of sound, c, Cc,) c=---_= lf k ( 7-13.7) (phase velocity) dw 7‘-14.2 group velocity cs CQ = dk (--1 7‘-15 sound energy w, (WJ, Mean sound energy in a given If the energy density varies ( 7- 14. I) density, (e) volume divided by that volume with time, the mean must be volumic sound taken over an interval during energy which the sound may be con- sidered statistically stationary. 7-l 6 sound power P, Pa Power emitted, transferred or i17-15. I) received as sound waves 7-l 7 sound intensity 1, J For unidirectional sound power, I(7-16. I) sound power through a surface normal to the direction of prop- agation divided by the area of the surface 4 IS 1890 (Part 7) : 1995 IS0 31-j: 199i Jnits ACOUSTICS (continued) International item Name of unit symbol for Definition Conversion factors and remarks No. unit ‘-9.a Pascal Pa bar (bar), 1 bar = 100 kPa (exactly) r-1 0.a metre m I-1 1 .a metre per second ~m/s r-12.a metre per second m/s* squared 7-13.a cubic metre per m3/s second 7-14.a metre per second m/s 7-15.a joule per cubic J/m3 metre 7-l 6.a watt W 7-l 7.a watt per square W/m* metre 5 IS 1890 (Part 7) : 1995 IS0 31-7 : 1992 4COUSTICS (continued) Quantities Item No.
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