SIST EN 27574-4:1997

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Akustik - Statistische Verfahren zur Festlegung und Nachprüfung angegebener (oder vorgegebener) Geräuschemissionswerte von Maschinen und Geräten - Teil 4: Verfahren für Angaben (oder Vorgaben) für Maschinenlose (ISO 7574-4:1985)Acoustique - Méthodes statistiques pour la détermination et le contrôle des valeurs déclarées d'émission acoustique des machines et équipements - Partie 4: Méthodes pour valeurs déclarées de lots de machines (ISO 7574-4:1985)Acoustics - Statistical methods for determining and verifying stated noise emission values of machinery and equipment - Part 4: Methods for stated values for batches of machines (ISO 7574-4:1985)17.140.20Emisija hrupa naprav in opremeNoise emitted by machines and equipmentICS:Ta slovenski standard je istoveten z:EN 27574-4:1988SIST EN 27574-4:1997en01-april-1997SIST EN 27574-4:1997SLOVENSKI
STANDARD
International Standard INTERNATIONAL ORGANIZATION FOR STANDARDlZATION*MEIKJLYHAPO~HAR OPfAHM3AL&lR fl0 CTAHAAPTt43A~klbl~ORGANISATlON INTERNATIONALE DE NORMALISATION Acoustics - Statistical methods for determining and verifying stated noise emission values of machinery and equipment - Part 4 : Methods for stated values for batches of machines Acoustique - Mbthodes statistiques pour Ia dktermination et Ie con trOle des valeurs d&clar&es d%mission acoustique des machines et kquipements - Partie 4 : M&hodes pour valeurs d&clar&es de fots de machines First edition - 1985-12-15 UDC 534.835.46 : 512.24 Ref. No. ISO 7574/4-1985 (El Descriptors : acoustics, machinery, noise (Sound), statistical quality control, statistical analysis. Price based on 14 pages SIST EN 27574-4:1997

Foreword ISO (the International Organitation for Standardization) is a worldwide federation of national Standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Esch member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take patt in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 7574/4 was prepared by Technical Committee ISO/TC 43, Acoustics. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. 0 International Organization for Standardization, 1985 Printed in Switzerland ii SIST EN 27574-4:1997

Contents Page 0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 Scope and field of application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 References. 1 3 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4 General . 1 5 Guidelines for the determination of the labelled value, L,, by the labeller. . 2 6 Verifying the labelled value for a batch of machines. . 3 6.1 General. 3 6.2 Single sampling inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 6.3 Double sampling inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 6.4 Sequential sampling inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7 Information to be given in a specific labelling code for a specific family ofmachines. 5 Annexes A Operating characteristic curves and examples of Single, double and sequential sampling. 6 B Guidelines for estimating Standard deviations and for the use of operating characteristic curves . . . . . . . . . . . . . . . . . . . . . I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 C Listofsymbols. 14 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 . . . Ill SIST EN 27574-4:1997

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INTERNATIONAL STANDARD ISO 75741401985 (E) Acoustics - Statistical methods for determining and verifying stated noise emission values of machinery and equipment - Part 4: Methods for stated values for batches of machines 0 lntroduction A general introduction to the four-part series of ISO 7574 is given in ISO 7574/1. For the purposes of this part of ISO 7574, the term “labelled value” Stands for all kinds of stated value (e.g. information on a label, the upper noise limit set by an authority, the agreed con- tract value) for which the methods may be applied. This part of ISO 7574 contains statistical sampling methods for checking the stated noise emission values for batches (lots) of machines. The labelled value for all machines in a batch is checked by sampling procedures. A reference Standard devia- tion is required when testing the compliance of a batch of a specific family of machines. In addition, information on the type of sampling to be used (Single, double or sequential) and the Sample size is required. The procedures specified in this part of ISO 7574 assume that the noise emission values of a batch (lot) of machines will follow a normal distribution. The statistical Parameters upon which this part of ISO 7574 is based assume that there is a 95 % probability of acceptance if no more than 6,5 % of the noise emission values in a batch exceed the labelled value. Information is included to assist the labeller in determining a labelled value based on these statistical Parameters. The methods given in this part of ISO 7574 ensure that a batch (lot) of machines labelled in accordance with the specifications for the verification procedure have a predetermined probability of acceptance. 1 Scope and field of application This patt of ISO 7574 provides guidelines for determining the labelled value, L,, by the labeller and specifies statistical sampl- ing procedures for verifying compliance of the noise emissions of a batch (lot) of machinery and equipment with its labelled value. This part of ISO 7574 is intended to assist those Parties respon- sible for drawing up specific labelling Codes for specific families of machines. lt is also intended to be of use to labellers who want their batches of machines to conform with verification procedures that are in accordance with the specifications given in the specific labelling Codes based on clause 7. This patt of ISO 7574 does not deal with the consequences that ensue if the stated value is not confirmed as verified for a batch (lot) of machines. 2 References ISO 3951, Sampling procedures and Charts for inspection by variables for percent defective. ISO 4871, Acoustics - Noise labefling of machinery and equip- ment. ISO 757411, Acoustics - Statistical methods for determining and verifying stated noise emission values of machinery and equipment - Part I : General considerations and definitions. 3 Def initions For the purposes of this part of ISO 7574, the definitions given in ISO 7574/1 apply. 4 General For a batch of machines, the noise emission values will cover a certain range due to the variability between the machines (rel- evant measure: Standard deviation of production, a,) and due to measurement errors occurring under reproducibility condi- tions (relevant measure : Standard deviation of reproducibility, OR - see 3.17 in ISO 7574/1). The measure for the Overall variability is the total Standard deviation, gt. The aim of labelling a batch of machines is to indicate as labelled value, L,, a limit below which a specified large propor- 1 SIST EN 27574-4:1997

ISO 757414-1985 (EI tion of the noise emission values of pressed as an integer in decibels. the batch shall lie. L, is ex- lt should be noted that fixing a and pl -a results in all operating characteristic curves (OCs) intersecting at the producer’s risk Point. When used for checking the compliance of a batch of machines with the labelled value, this part ISO 7574 works on the prin- ciple that only a Sample from the batch is measured. This prin- ciple is appropriate for mass-produced machines. This part of ISO 7574 considers the need to control machines which are too noisy compared with the labelled value; therefore, it applies to one-sided cases for checking an upper limit, not to two-sided cases which would also exclude machines which are too quiet. The principle is based on balancing risks which are expressed by a pair of values : a specified proportion, .ul _ Ul of noise emis- sion values of the batch exceeding the labelled value and a specified probability of rejection, a, for a lot with this propor- tion pl -a. If the actual total Standard deviation is different from the reference Standard deviation GM, guidance for the labeller is given in clause 5 and annex B. NOTE - In the application of this part of ISO 7574, it is assumed that all measurements will be performed by a testing laboratory which has appropriate test facilities and trained staff. 5 Guidelines for the determination of the labelled value, Lc, by the labeller As the determination of the labelled value for a batch of machines is the sole responsibility of the labeller, this clause is given for guidance only to provide a predictable probability of acceptance. Verifying compliance of the lot on the following assumptions : with the labelled value is a) that the noise emission values of the batch approximate to a normal distribution, characterized by the mean value ,u and the specified reference Standard deviation aM; and L, tan only be determined in accordance with this part of ISO 7574 if a specific labelling code in conformity with clause 7 exists [See, in particular, 7 c) to f)]. b) that the rejection probability for a batch is equal to a specified value a if the labelled value L, is Chosen so that the proportion of noise emission values of the batch ex- ceeding L, is equal to the specified value pl -a. A reasonably large number of measured values of individual machines, Lz are determined in accordance with the specific measurement test code for the specific family of machines. (The asterisk in the Symbols is used here to differentiate be- tween measurements in conformity with this clause and those in conformity with clause 6.) Procedures in this part of ISO 7574 are based on a = 5 % and Pl-Q! = 6,5 %. The mean calculated machines value, from -* L ’ and the total Standard the measured values, Lz mple (see also clause 8.2). deviation, st* are of the individual NOTE - The fixed value of 6,5 % was Chosen in Order to comply with the definition for L,; in a sa - to make sure that the differente the batch is reasonably limited; and between L, and the mean for z* and .s+* are estimates of the mean value,u and dard deviation , ot, of the batch to be labelled. the total stan- - to achieve a common understanding, comparability and com- patibility of different L, values for different machines from different families of machines. In accordance with clause B.3, equation (161, the following equations will provide guidance for the labeller who wants to have a probability of acceptance, P,, defined by himself: If the batch and the labelled value, L,, conform with these values, the sampling inspection procedures are set in such a way that the batch will be accepted with the probability of l- a = 95 % and the mean value will be expected to lie ap- proximately 1’5 GM below the labelled value. L, = fora, = aM . . . (1) L, = NOTES fora, # 0~ l W* (2) 1 If it is explicitly known that a stated value is not an upper value as L, but represents a mean value (which is not in accordance with ISO 4871), the checking procedure might also be used by adding 1’5 UM to this mean value to obtain L,. where P is the mean value of the batch; 2 Methods for estimating risk factors are given in annexes A and B; they may be replaced by repeated, simulated application of the check- ing procedure using actual measurement data, if the assumption that the noise emission values of the batch approximate to a normal distribution is uncertain. Normality tests will be described in a future International Standard. n is the specified verification Sample size for Single sam- pling inspection (6.2) or the equivalent Single Sample size in the case of double sampling inspection (sec 6.3) or sequen- tial sampling inspection (see 6.4); k is a function of n, in accordance with table 1; 3 The sampling inspection by variables for isolated batches of machines, as described in this part of ISO 7574, broadly conforms to ISO 3951 which is, however, designed for the inspection of batches from continuous production. ISO 3951 does not provide for double and sequential sampling inspection, and the operating characteristic curves do not intersect exactly at the producer’s risk Point; this is, however, the aim of this part of ISO 7574 with the view to establishing the mean- ing of L, unambiguously. upa is the quantile of the normal distribution for the value P, (see table 7); UM is the verif ication; specif ied reference Standard deviation for is the actual total Standard deviation. 2 SIST EN 27574-4:1997

If the labeller accepts a risk of rejection of 5 % (i.e. he wants to repeatability conditions (sec 3.16 in ISO 7574/1). lt shall be have a probability of acceptance, Pa, of 95 %), the above equa- ascertained that no outstanding systematic error of measure- tions result in the following 1) : ment results is connected with relevant laboratories. L, = p + 1,5 OM fora, = UM . . . (3) Lc = ,td + 1,5 bt + k(aM - 0,) fora, f: GM . . . (4) For examples, see clause 8.3. For each of the procedures outlined in 6.2 to 6.4, the measured values, Li, shall be determined in accordance with the specific measurement test code for the specific family of machines [see clause 7 c) and d)l. The measured values shall not be rounded Prior to statistical calculations. NOTE - Testing may be necessary from time to time in Order to ensure that the labelled value continues to be correct. Testing is also required whenever physical changes are made to the production machines that may affect their noise emissions. 6.2 Single sampling inspection 6 Verifying the labelled value for a batch of machines In accordance with 6.1 and clause 7, n and oM have been specified for the relevant family of machines. Take at random a Sample of size n from the batch under con- sideration. 6.1 General Three equivalent procedures for verifying the labelled value of the batch are described in this part of ISO 7574: Single sam- pling, double sampling and sequential sampling. The results obtained from any one of the three procedures will generally be the same if the assumption that the emission values are distributed approximately as a normal distribution is valid. The measured values are Li (i = 1, . . . . n) and their mean value is 1 n zz-- Li c . . . n (5) i=l Determine the value One and only one of the three procedures shall be Chosen and specified in the labelling code for each specific family of machines (see clause 7). All three procedures require a specified reference Standard deviation, OMI for each specific family of machines. A = L, - kOM . . . 6) using the acceptability constant k calculated from the formula The Sample size, n, in the case of Single sampling (or equivalent Sample sites nl and 122 in the case of double sampling or equivalent maximum sample size n,, in the case of sequential sampling) shall also be specified for each specific family of machines (see annex AI. In general, double or sequential sampling results in a somewhat smaller number of machines being tested. k=qep, aU1-a -a 6 . . . (7) where Ul -Pl-a = 1,514 u1 - a = 1,645 NOTE - The reason for applying only one of the three procedures for a specific family of machines is that the procedures are only equivalent provided that the assumption of normality is absolutely valid. are the quantiles of the standardized normal distribution for the values 1 - ~1 _ a = 93,5 % and 1 - a = 95 % respec- tively. The procedures outlined in 6.2 to 6.4 are applicable for reproducibility conditions (see 3.17 in ISO 7574/1), and for Table 1 gives the values for k for different sample sizes II. Table 1 - Acceptability constant k for different Sample sizes n . n 1 2 3 4 5 6 7 8 9 10 k - 0,131 0,351 0,584 0,692 0,778 0,842 0,892 0,932 0,988 0,994 . 1) upa #l-a Use equation (1) or (2)’ by replacing - with - = 6 6 ‘1 ‘Pl -a - k [See equation (711 where u1 -p1 _ a = 1’5. SIST EN 27574-4:1997

ISO 7574144985 (El Make the decision on the acceptability of the labelled value using the following rules: * Determine the value if E < A, the labelled value is confirmed as verified for the batch ; if c > A, the labelled value is not confirmed asverified for the batch. . . .- NOTE - See example in A.4.1. 6.3 Double sampling inspection In accordance with 6.1 and clause 7, q, n2 and aM have been specified for the relevant family of machines. Take at random a Sample of specified size nl from the batch In accordance with 6.1 and clause 7, n,,, and q,, have been under consideration. specified for the relevant family of machines. The measured values are Li (i = 1, . . ., n,) and their mean value is E. Determine the values A = L, - k,Q . . . (8) B = L, - k,Q . . . (9) using the acceptability constants k, and k, given in table 2. Table 2 - Acceptability constants k,, k, and kd for double sampling and equivalent Sample sizes (single/double) Double sampling I Equivalent Single sampling nl I n2 I k 1 h 1 kd 1 n 0,863 - 0,210 0,191 1,194 - 0,201 0,533 u334 0,235 0,632 1,649 - 0,130 0,774 1,553 - 0,228 0,848 1,750 0,057 0,892 1,504 0,302 0,938 2,083 ~ 0,018 0,962 NOTE - The only double sampling Plans given are those whose operating characteristic curves are nearest to the operating characteristic curves for the equivalent Single sampling Plans. Make the decision on the acceptability of the labelled value using the following rules: if z < A, the labelled value is confirmed as verified for the batch; if z > B, the labelled value is not confirmed as verified for the batch ; if A < E < B, take a second Sample of specified size 9. The measurement values of both samples are Li (i = 1, . . . , nl + 122) .and their total mean is &. c = L, - k&,j . . . (101 using kd from table 2. If Et G C, the labelled value is confirmed as verified for the batch. If & > C, the labelled value is not confirmed as verified for the batch. NOTE - See example in A.4.2. 6.4 Sequential sampling inspection Start with the first item taken from the batch under considera- tion. After each test, calculate the following summation from the y1* results Li that have been obtained: n” s,t = c (Li - b) . . . (11) i=l where b is taken from the appropriate column in table 3. Table 3 - Acceptability values a, b and r for sequential sampling and equivalent Sample sizes (singlehequential) Sequential sampling I Equivalent Single sampling I a 1 r I n 3 - 1,267 OM 5 - 1,552 OM 6 - 1,791 GM 8 - 2,000 OM 9 - 2,186 CtM 11 - 2,362 OM 12 - 2,524 CtM 14 - 2,680 GM 15 - 2,823 GM L, - 0,351 aM L,-o,!%b, L, - 0,692 OM L, - o,n80M L, - 0,8420, L, - 0,892aM L, - 0,932oM L, - 0,%6a, L, - 0,99bM 1,267 aM 1,552 aM 1,791 oM 2,m OM 2,188 OM ~ 2,362 GM 2,524 OM 2,680 OM 2,8
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