1、BRITISH STANDARD BS ISO 16063-12:2002 Methods for the calibration of vibration and shock transducers Part 12: Primary vibration calibration by the reciprocity method ICS 17.160 BS ISO 16063-12:2002 This British Standard, having been prepared under the direction of the Engineering Sector Policy and S
2、trategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 29 July 2002 BSI 29 July 2002 ISBN 0 580 40125 1 National foreword This British Standard reproduces verbatim ISO 16063-12:2002 and implements it as the UK national standard. It supersedes BS 6955-2
3、0:1997 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee GME/21, Mechanical vibration and shock, to Subcommittee GME/21/2, Vibration and shock measuring instruments and testing equipment, which has the responsibility to: A list of organizations represen
4、ted on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by usin
5、g the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity
6、from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in t
7、he UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to iv, pages 1 to 20, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publi
8、cation Amd. No. Date Comments Reference number ISO 16063-12:2002(E)INTERNATIONAL STANDARD ISO 16063-12 First edition 2002-04-01 Methods for the calibration of vibration and shock transducers Part 12: Primary vibration calibration by the reciprocity method Mthodes pour ltalonnage des transducteurs de
9、 vibrations et de chocs Partie 12: talonnage primaire de vibrations par mthode rciproque BSISO1606312:2002ii BSISO1606312:2002 iiiContents Page Foreword.iv 1 Scope 1 2 Normative references1 3 Uncertainty of measurement 1 4 Symbols1 5 Requirements for apparatus.2 6 Ambient conditions .4 7 Preferred a
10、mplitudes and frequencies4 8 Procedure .4 9 Computation of sensitivity6 Annex A (normative) Calculation of uncertainty10 Annex B (informative) Application of the theory of reciprocity to the calibration of electromechanical transducers 14 Bibliography20 BSISO1606312:2002iv Foreword ISO (the Internat
11、ional Organization 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. Each member body interested in a subject for which a technical committee has bee
12、n established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical stand
13、ardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for
14、 voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO 16063 may be the subject of patent rights. ISO shall not be held responsible for identifying a
15、ny or all such patent rights. ISO 16063-12 was prepared by Technical Committee ISO/TC 108, Mechanical vibration and shock, Subcommittee SC 3, Use and calibration of vibration and shock measuring instruments. ISO 16063 consists of the following parts, under the general title Methods for the calibrati
16、on of vibration and shock transducers: Part 1: Basic concepts Part 11: Primary vibration calibration by laser interferometry Part 12: Primary vibration calibration by the reciprocity method Part 13: Primary shock calibration using laser interferometry Part 21: Vibration calibration by comparison to
17、a reference transducer Part 22: Secondary shock calibration Annex A forms a normative part of this part of ISO 16063. Annex B is for information only. BSISO1606312:2002 1Methods for the calibration of vibration and shock transducers Part 12: Primary vibration calibration by the reciprocity method 1
18、Scope This part of ISO 16063 specifies the instrumentation and procedures to be used for primary calibration of accelerometers using the reciprocity method and the SI system of units. It is applicable to the calibration of rectilinear accelerometers over a frequency range of 40 Hz to 5 kHz and a fre
19、quency-dependent amplitude range of 10 m/s 2to 100 m/s 2and is based on the use of the coil of an electrodynamic vibrator as the reciprocal transducer. Calibration of the sensitivity of a transducer can be obtained using this part of ISO 16063 provided that the signal conditioner or amplifier used w
20、ith the transducer during calibration has been adequately characterized. In order to achieve the uncertainties of measurement given in clause 3, it has been assumed that the transducer has been calibrated in combination with its signal conditioner or amplifier (the combination of which in this part
21、of ISO 16063 is referred to as the “accelerometer”). 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO 16063. For dated references, subsequent amendments to, or revisions of, any of these publi
22、cations do not apply. However, parties to agreements based on this part of ISO 16063 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies
23、. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 266, Acoustics Preferred frequencies ISO 16063-1:1998, Methods for the calibration of vibration and shock transducers Part 1: Basic concepts 3 Uncertainty of measurement At a reference frequency of 160 Hz and
24、 a reference amplitude of 100 m/s 2 , 50 m/s 2 , 20 m/s 2or 10 m/s 2 , the applicable limits of uncertainty are 0,5 % of the modulus (magnitude) of complex sensitivity and 1 of the argument (phase shift) of complex sensitivity. Over the full range of amplitudes and frequencies, the limits of uncerta
25、inty in the measured magnitude and phase shift of sensitivity are 1 % and 2, respectively. All users of this part of ISO 16063 are expected to make uncertainty budgets according to annex A to document the uncertainty of measurement. The uncertainty of measurement is expressed as the expanded measure
26、ment uncertainty in accordance with ISO 16063-1 (referred to here as “uncertainty”). 4 Symbols A general list of symbols used in this part of ISO 16063 is contained in Table 1. Specific symbols used in formulae are defined following the formulae in which they appear. BSISO1606312:20022 Table 1 Gener
27、al symbols Symbol Definition Unit f frequency of vibration Hz n indices of test masses (n = 0 indicates no test mass) m nmass of the test mass number n kg u complex voltage V U complex voltage ratio Y complex electrical admittance S R electrical resistance complex intercept of least-squares fit kg c
28、omplex slope of least-squares fit S acomplex sensitivity of the calibrated accelerometer V/(ms 2 ) |S a | modulus (magnitude) of S aV/(ms 2 ) aargument (phase shift) of S adegree Re real part of a complex quantity Im imaginary part of a complex quantity | | modulus or absolute value of a complex qua
29、ntity arg argument of a complex quantity 5 Requirements for apparatus 5.1 General The case of the transducer shall be structurally rigid over the frequency range of interest. The sensitivity to base strain and transverse motion and the stability of the accelerometer (transducer in combination with t
30、he signal conditioner or amplifier) shall be included in the calculation of the expanded uncertainties in determining the modulus and argument of complex sensitivity (see annex A). 5.2 Frequency generator and indicator or counter Use equipment having the following characteristics: a) maximum uncerta
31、inty in frequency: 0,01 %; b) change in frequency: less than 0,01 % over each measurement period; c) change in amplitude: less than 0,01 % over each measurement period. 5.3 Power amplifier/vibrator combination Use equipment having the following characteristics for all measurement conditions: a) maxi
32、mum total harmonic distortion: 2 %; b) transverse, bending and rocking acceleration: commensurate with the uncertainty of the measured sensitivity (typically 10 % of the acceleration in the intended direction over the frequency range of interest); c) minimum ratio of signal to noise at the output of
33、 the accelerometer: 30 dB; d) change in acceleration amplitude: less than 0,05 % over each measurement period. BSISO1606312:2002 35.4 Seismic block for vibrator The vibrator shall be mounted on a massive rigid seismic block so as to minimize the reaction of the vibrator support structure to the moti
34、on of the vibrator from significantly affecting the uncertainty in the calibration results. The mass of the seismic block should be at least 2 000 times that of the moving element of the vibrator. Examples of seismic blocks suitable for this use include granite blocks or steel honeycomb optical tabl
35、es. The seismic block should be vibration isolated with vertical and horizontal suspension resonances of less than 2 Hz if significant seismic vibration exists in the calibration environment. 5.5 Instrumentation for complex voltage ratio measurements Use equipment having the following characteristic
36、s: a) frequency range: 40 Hz to 5 kHz; b) maximum uncertainty in the modulus (magnitude) of complex voltage ratio: 0,1 %; c) maximum uncertainty in the argument of complex voltage ratio: 0,1. 5.6 Resistor The resistor shall have a maximum uncertainty in the determination of its resistance of 0,05 %
37、over the calibration frequency range and the range of power dissipated. Ensure that the value of the impedance of the standard resistor used to determine current does not vary appreciably due to inductive and thermal effects. 5.7 Set of test masses The test masses shall a) cover a range of at least
38、five approximately equal intervals, with the largest test mass between approximately 0,5 to 1 times the mass of the moving element of the vibrator, and b) have a maximum uncertainty in the determination of mass of 0,05 %. It is recommended that the shape of the test masses be similar to that of a cu
39、be or cylinder with a length-to-width ratio of approximately one. The maximum frequency at which the test mass behaves as a rigid body can then be estimated by use of the formula: c/(2L) where c is the speed of sound in the material of the test mass and L is its length. The surface finish specificat
40、ions and the machining tolerances of the mounting hardware of the test masses should meet or exceed the requirements specified for mounting the transducer being calibrated. This is particularly critical if calibrations are performed at high frequencies. The test masses should be machined from a rela
41、tively stiff material such as tungsten carbide to maximize the frequencies of the natural resonances occurring in them. In practice, the number and size of the test masses selected will be a compromise between reducing the statistical uncertainty versus increasing the measurement uncertainty due to
42、thermal effects occurring in the drive coil as a result of making a relatively large number of measurements with large differences in measured electrical admittance. 5.8 Distortion-measuring instrumentation Use equipment capable of measuring a total harmonic distortion of 0,01 % to 5 % and having th
43、e following characteristics: a) frequency range: 40 Hz to 5 kHz; b) maximum uncertainty: 10 % of the measured value of distortion. BSISO1606312:20024 5.9 Oscilloscope While an oscilloscope is useful for examining the waveforms of the accelerometer and electrodynamic moving coil, its use is not manda
44、tory. 5.10 Air-handling equipment This shall be capable of maintaining the ambient conditions within the requirements specified in clause 6. 6 Ambient conditions Calibrations shall be carried out under the following ambient conditions: a) room temperature: (23 3) C; b) maximum relative humidity: 75
45、%. 7 Preferred amplitudes and frequencies The amplitudes and frequencies of acceleration used during calibration should be chosen from the following series: a) acceleration: 10 m/s 2 , 20 m/s 2 , 50 m/s 2 , 100 m/s 2 ; b) reference acceleration: 100 m/s 2 , 50 m/s 2 , 20 m/s 2or 10 m/s 2 ; c) freque
46、ncy: selected from the standardized one-third-octave frequencies given in ISO 266 from 40 Hz to 5 kHz; d) reference frequency: 160 Hz. Calibrations performed at large acceleration amplitudes could have relatively large uncertainties due to thermal effects occurring in the drive coil. 8 Procedure 8.1
47、 General Calibration of electromechanical transducers by reciprocity utilizes the linear bilateral relationship between the electrical and mechanical terminals of the transducers being calibrated. Three transducers are required in order to perform an absolute calibration of two of the transducers. O
48、ne transducer is used only as a vibration sensor, one is used only as a vibration source, and one is used reciprocally as both a vibration sensor and a vibration source (generator). In principle, the electromechanical coupling of the reciprocal transducer can be either electrodynamic or piezoelectri
49、c. However, in practice, electrodynamic transducers are much more widely used as the reciprocal transducer in vibration calibrations by reciprocity. Therefore, the methods described in this part of ISO 16063 are based on the use of the coil of an electrodynamic vibrator as the reciprocal transducer with the coil located in close proximity to the transducer being calibrated. The transducer that is used only as a vibration source may be either a s
