1、CENELEC EN*bL*329 96 3404583 OL7LO4 BT9 BRITISH STANDARD Sound system equipment - Methods of measuring and specifying the performance of sounders (electroacoustic transducers for tone production) The European Standard EN 61329 : 1996 has the status of a British Standard ICs 33.160.30 NO COPYING WITH
2、OUT BSI PERMISSION EXCEPT AS PERMITED BY COPYJtIGHT LAW BS EN 61329 : 1996 IEC 1329 : 1995 CENELEC EN*b1*329 96 = 3404583 0177105 735 BS EN 61329 : 1996 This British Standard, having been prepared under the direction of the Eleclx In figures 4 and 5 (see 5.6.1) has been replaced by (see 5.5.1). Comp
3、liance with a British Standard does not of itself confer immunity from legal obligations. ii O BSI 1996 CENELEC EN*bl*329 b m 3404583 0177108 444 EUROPEAN STANDARD EN 61329 NORME EUROPENNE EUROP piezoelectric ceramic disc: Thin plate made of a piezoelectric ceramic, for example lead zirconate titana
4、te (PT) ceramic, of which each side is metallized. The ceramic plate is polarized so as to deform radially when a voltage is applied across it. 3.2 Characteristics, symbols and units 3.2.1 sounder or a piezoelectric diaphragm. Symbol: Urms, unit: V. input voltage (sinusoidal signal): RMS voltage of
5、a sinusoidal signal applied to a 3.2.2 applied to a sounder. Symbol: Upp, unit: V. input voltage (square wave signal): Peak-to-peak voltage of a square-wave signal NOTE - The sounder or piezoelectric diaphragm may require, or tolerate, a d.c. component in addition to the square wave, in which case t
6、he required or tolerated signal waveform will be specified, as illustrated in figure 1. 3.2.3 d.c. polarity (of an electromagnetic or an electrodynamic sounder): Direction of the d.c. component applied to an electromagnetic or electrodynamic sounder which is designed to be driven by a positively-bia
7、sed or negatively-biased square-wave input voltage. CENELEC EN*bl*32 b = 3404583 OL77LL2 975 = Page 6 EN 61329 : 1996 3.2.4 voltage, applied for polarization of the piezoelectric ceramic during production. direction of polarization (of a piezoelectric ceramic plate): Direction of the d.c. 3.2.5 reso
8、nant frequency (of a sounder): Frequency within the rated frequency range, at which the output sound pressure of a sounder shows a local maximum. Symbol: fr, unit: Hz. 3.2.6 resonant frequency (of a piezoelectric diaphragm): Frequency close to the eigenfrequency of the first symmetrical vibration mo
9、de for the free boundary condition, at which the electrical impedance of the piezoelectric diaphragm shows a local minimum. Symbol: fr, unit: Hz. 3.2.7 anti-resonant frequency (of a piezoelectric diaphragm): Frequency close to the eigenfrequency of the first symmetrical vibration mode for the free b
10、oundary condition, at which the electrical impedance of a piezoelectric diaphragm shows a local maximum. Symbol: fa, unit: Hz. 3.2.8 sensitivity level to voltage (with A-weighting): Output sound pressure level of a sounder measured using a sound level meter with A-weighting, referred to an input vol
11、tage of 1 V and to a distance of 1 m. The measuring frequency and input signal waveform are as specified by the manufacturer. Symbol: SA, unit: dB ref. 20 pPa. NOTE - The A-weighting characteristic is specified in IEC 651. 3.2.9 distance to measuring point: Distance between the reference point of a
12、sounder to be measured and the reference point of the microphone used for the measurements, specified as one of the measuring conditions. Symbol: r, unit: m. 3.2.1 O principal axis (of microphone): Line through the geometrical centre, and perpendicular to the reference plane, of the microphone used
13、for measurement. NOTE - The front surface of the microphone should be taken as the reference plane, if the reference plane of the microphone is not specified by the manufacturer. 3.2.11 reference point (of microphone): Point where the principal axis of the microphone intersects the reference plane.
14、For additional information, see note to 3.2.10. 4 Rated conditions For a full explanation of the terms rated value and rated condition, see IEC 268-2. The following conditions shall be specified by the manufacturer of the sounder. 4.1 Rated input voltage The continuous input voltage at which the sou
15、nder operates normally for the specified period of time. The frequency and waveform of the input signal shall be specified. Symbol: Ur, unit: V. CENELEC EN*bL*329 96 = 3404583 OL77LL3 801 M Page 6 EN 61329 : 1996 4.2 Rated maximum input voltage The maximum voltage which can be applied to the sounder
16、 for a specified short time. The frequency and waveform of the input signal shall be specified. Symbol: Um, unit: V. 4.3 Rated frequency range The frequency range for continuous sinusoidal input signal over which the sounder can operate normally. The input voltage shall be specified. 4.4 Rated resis
17、tance The d.c. resistance of an electromagnetic or electrodynamic sounder specified for matching purposes. Symbol: Rr, unit: i2 4:5 Rated capacitance The electrical capacitance of the piezoelectric sounder specified for matching purposes. Symbol: Cr , unit: nF. 4.6 Principal axis (of sounder) The li
18、ne through the geometrical centre of the sound hole(s), perpendicular to the front surface of the sounder. For additional information, see note to 4.7. 4.7 Reference point (of sounder) The point where the principal axis of the sounder intersects the front surface. NOTE - Strictly. this term and that
19、 defined in the previous subclause should include the word rated (for example. rated reference point), since they are specified by the manufacturer in accordance with these definitions and cannot be measured, but confusion is unlikely even if the shorter terms are used. 4.8 Rated working temperature
20、 range The environmental temperature range over which a sounder can operate normally. 5 Characteristics and measuring methods 5.1 Measuring conditions 5.1 .l Environmental noise and other interferences The disturbance of measured sound pressure level due to environmental or other noises shall not ex
21、ceed 1 dB. 5.1.2 Climatic and environmental conditions Unless otherwise specified by the manufacturer, measurements shall be made under the following environmental conditions: 15 OC to 35 “C, preferably at 20 OC; - ambient temperature: CENELEC EN*bL*32 b = 3404583 0177114 746 Page 7 EN 61329 : 1996
22、- relative humidity: 25 Yo to 75 Yo - air pressure: 86 kPa to 106 kPa. NOTE - For further information, see IEC 268-1, IEC 68 and IEC guide 106. 5.1.3 Acoustic environment for measurement In the frequency range 500 Hz to 10 kHz, the variation, due to acoustic reflections or reverberation, of sound pr
23、essure level with distance shall not deviate by more than 1 dB from the response in an ideal free sound field, in the range of distance from 0,l m to that of the measuring point. 5.1.4 Measuring signal waveform The waveform of the signal for measurement shall be sinusoidal or square. The signal volt
24、age shall be stated as the r.rn.s. value for a sinusoidal signal and as the peak-to-peak value for a square wave signal. For a square-wave signal, information on any necessary d.c. component shall be given (see figure 1). 5.2 Measuring equipment 5.2.1 Sound level meter A sound level meter conforming
25、 to the requirements of IEC 651 shall be used. The weighting characteristic A shall be used except for the frequency response measurement. The dynamic characteristic F shall be used for all the measurements. The S characteristic may be used only if the difference in the measurement is negligible. 5.
26、2.2 Microphone for measurement A microphone as described in IEC 1094-1 or IEC 1094-4 shall be used. Either the pressure type (P type) or the free-field type (F type) may be used. 5.2.3 Automatic frequency response recorder Interruption of the signal frequency trace at any instant during the measurem
27、ent should not affect the indicated response by more than 1 dB. 5.2.4 Sinusoidal signal generator and amplifier The amplifier associated with a sinusoidal signal generator shall conform with the following requirements: a) the amplifier shall be stable when connected to the sounder under the test; b)
28、 the variation of the output voltage across the test load (see below) shall be less than 0,5 dB, and the total harmonic distortion of the output signal shall be less than 1 %, at any frequency within the rated frequency range of the sounder under test. The applied signal voltage shall be the rated i
29、nput voltage of the sounder to be measured. The signal frequency shall be varied within the rated frequency range of the sounder. CENELEC EN*h3*329 96 m 3404583 0377335 b84 Page 8 EN 61329 : 1996 The test load of the amplifier for the measurement of an electromagnetic or an electrodynamic sounder sh
30、all be a resistance of the same value as the rated resistance of the sounder. The test load of the amplifier for the measurement of a piezoelectric sounder shall be a capacitor of the same value as the rated capacitance of the sounder; c) the output level across the rated load impedance of the ampli
31、fier shall not differ by more than 1 dB from that across a load of 10 times the rated load impedance. 5.2.5 Square-wave signal generator and amplifier The amplifier associated with a square wave generator shall conform with the following requirements: a) the amplifier shall be stable when connected
32、to the sounder under test; b) the rise and fall times of the output voltage across the test load (see below), which are the times from the instant when the waveform reaches 10 % of the final amplitude to the instant when the waveform reaches 90 % of the final amplitude, shall be less than 5 % of the
33、 signal period. The applied signal voltage shall be the rated input voltage of the sounder to be measured. The signal frequency shall be varied within the rated frequency range of the sounder. The test load of the amplifier for the measurement of an electromagnetic or an electrodynamic sounder shall
34、 be a resistance of the same value as the rated resistance of the sounder. The test load of the amplifier for the measurement of a piezoelectric sounder shall be a capacitor of the same value as the rated capacitance of the sounder; c) the output voltage waveform shall not overshoot or undershoot by
35、 more than 25 % of the full amplitude; d) the output level across the rated load impedance of the amplifier shall not differ by more than 1 dB from that across a load of 10 times the rated impedance. 5.2.6 Capacitance meter The measurement accuracy of the capacitance meter shall be 15 %, or better,
36、at the frequencies of 120 Hz and 1 kHz. 5.2.7 Resistance meter The measurement accuracy of the d.c. resistance meter shall be +5 %, or better. 5.3 Electroacoustic transducer characteristics of the sounder 5.3.1 Sensitivity level to voltage The sensitivity level to voltage of a sounder is obtained fr
37、om the output sound pressure level measured at the specified point on the reference axis, with the input signal voltage equal to the rated input voltage, by the following equation: SA = L + 20 iog(UdUr) + 20 log(r/ro) (dB) where SA is the sensitivity level to voltage; CENELEC EN*b1*327 76 W 3404583
38、017711b 510 Page 9 EN 61329 : 1996 L U, Ur r is the measuring distance; ro is the measured output sound pressure level; is the reference input voltage, 1 V; is the rated input voltage; is the reference distance, 1 m. The measuring distance, between 0,l m and 1 m, shall be specified by the manufactur
39、er. The output sound pressure level is measured by using a sound level meter with A-weighting, as shown in figure 2. An F type measuring microphone (see IEC 1094) shall be set face-to-face with the sounder (see figure 2a) while a P type shall be set sideways (see figure 2b). Additional devices, caus
40、ing acoustic diffraction, such as a baffle board, shall not be used. The waveform of the input signal, which shall be sinusoidal or square, and the frequency of the input signal, which shall be within the rated frequency range, shall be specified by the manufacturer. NOTE - One of the following meas
41、uring distances is recommended: 0,l m, 0,3 m, 0,5 m or 1 m. 5.3.2 Frequency response The frequency response of a sounder is the output sound pressure level at a specified point on the reference axis, with the rated input voltage applied to the sounder, expressed graphically as a function of frequenc
42、y. The input signal waveform shall be sinusoidal. If the rated input voltage is specified as square wave, the r.m.s. value of the applied sinusoidal voltage shall be half the rated (peak-to-peak) input voltage. Although the frequency range for measurement shall be specified by the manufacturer, 500
43、Hz is recommended for the lower limit and 10 kHz for the upper limit. For sweep-frequency measurements, with automatic plotting of the result, the sweep from lower to higher frequencies is preferred if the direction of sweep affects the results. The measuring system is the same as for the sensitivit
44、y measurement, given in figure 2, except the sound level meter with A-weighting shall be replaced by a sound level meter with “Lin“ frequency characteristic, and, preferably, a level recorder. Other items shall be the same as specified in 5.3.1. NOTE - The frequency response of the sounder can be ob
45、tained by means of any measuring method using a noise or an impulse input signal and a necessary signal processing technique, provided the results are equivalent to that obtained by the preceding sinusoidal measuring method. 5.3.3 Listening test for normal operation As shown in figure 3, the normal
46、operation of a sounder shall be examined by listening to the output sound at a point convenient to distinguish abnormal tones. The input signal shall be sinusoidal or square of the rated input voltage, and the frequency shall be varied within the rated frequency range. CENELEC EN*b1*329 96 3404583 O
47、L77LL7 457 W Page 10 EN 61329 : 1996 The distance from the reference point of the sounder to the listening point shall be 0,3 m unless the manufacturer specifies the distance. The distance shall be increased if the output level of the sounder is so high that the examiners exposure to sound becomes e
48、xcessive. 5.4 Electrical and mechanical characteristics of sounders 5.4.1 Resonant frequency The resonant frequency of a sounder shall be measured using a sinusoidal signal of one of the following frequency points: a) the frequency at which the output sound pressure of the sounder shows the most sig
49、nificant local maximum in the rated frequency range. The method of measuring frequency response is given in 5.3.2; b) for an electromagnetic or an electrodynamic sounder, the frequency where the electrical impedance of the sounder shows a local maximum. The applied signal voltage shall be specified by the manufacturer. The signal frequency should be varied from lower to higher frequencies; c) for a piezoelectric sounder, the frequency where the electrical impedance of the sounder shows a local minimum. The applied signal voltage shall be 1 V, or less. The signal fre
