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GB/T 159521995
This standard is formulated based on the International Electrotechnical Commission standard IEC1252 Specifications for personal sound exposure meters (Specifications for personal sound exposure meters IEC1553-6th edition). As this international standard is technically mature and is an important dose indicator for noise hearing protection in the field of environmental protection, it will promote the use of noise workers in my country, so it is adopted as an equivalent to meet the needs of international trade technology and economic exchanges and the adoption of international standards as soon as possible.
This standard shall be implemented from August 1, 1996. The appendix A and appendix B of this standard are both informative appendices. This standard was proposed by the Chinese Academy of Metrology. The drafting unit of this standard: China Institute of Metrology. The main drafters of this standard: Zhang Jucai, Qiu Jianhua. GB/T15952—1995
IEC Foreword
1) IEC (International Electrotechnical Commission) is a worldwide standardization organization including national electrotechnical committees (IEC National Committees). The purpose of IEC is to promote international cooperation on standardization issues in the electrical and electronic fields, and to this end, in addition to other activities, publish international standards. The formulation work is entrusted to technical committees. Any IEC National Committee with interested technical content can participate in the formulation work, and international, governmental and non-governmental organizations related to IEC can also participate in the formulation. According to the agreement reached between the two major organizations, IEC and the International Organization for Standardization (ISO) work closely together. 2 Formal resolutions or agreements formed by technical committees on technical content of common interest to national committees, as far as possible, clarify the international consensus on the issues involved. 3) The recommendations they form are for international use and are published in the form of standards, technical reports and guidelines. In this sense, they are accepted by national committees.
4) In order to promote international uniformity, each IEC National Committee shall clearly apply IEC International Standards to national or regional standards to the greatest extent possible; any inconsistencies between IEC standards and corresponding national or regional standards shall be explained in the latter. 5) TEC does not provide a marking procedure to indicate its approval and cannot be responsible for any equipment that conforms to one of its standards. International Standard IEC 1252 was prepared by IEC Technical Committee 29: "Electroacoustics". The text of this standard is based on the following documents: DIS
29(CO)162
Voting Report
29(C0)168
Full technical voting information for the approval of this standard can be found in the voting report indicated in the table above. The technical requirements for personal sound exposure meters of the international standard are coordinated with the technical requirements for the comparable IEC804:1985 integrating sound level meters in the practical range. The four main technical differences are: a) the measurement basis and the indicated sound exposure are not equivalent continuous A-frequency weighted sound pressure levels or sound exposure levels; b) the accuracy of the squared and integrated short-duration compensation signals is specified by measuring the sound exposure of a sequence of repeated constant amplitude 4kHz tone bursts of duration from 1ms to 10 1ms, not by measuring a single 4 kHz tone burst response with variable amplitude from 1 ms to 1 s, each single tone burst accompanied by a continuous, in-phase, low-level 4kHz background signal; c) the specifications for personal sound exposure meters include limits on the difference in sound exposure between the positive and negative monopolar pulses; d) the requirements for the directivity of microphones for sound exposure meters to be worn on the human body are not specified. This international standard consists of two references. Annex A provides a table of selected sound exposures and corresponding normalized 8h average sound levels, and Annex B describes recommended tests for verifying the performance of personal sound exposure meters. GB/T15952—1995
According to the intent of this standard, personal sound exposure meters are used to measure sound exposure, which is the time integral of the square of the instantaneous A-frequency weighted sound pressure. The operating principle is based on the measurement of sound exposure levels in accordance with IEC801:1985. This is the "equal energy exchange rate", i.e. doubling (or halving) the integration time of a constant sound level also doubles (or halves) the sound exposure. Similarly, increasing (or decreasing) the constant input sound level of a constant integration time by 3 dB doubles (or halves) the sound exposure.
Noise dosimeters are usually designed to indicate noise dose as a percentage of the legal limit. The legal limits and their definitions vary from country to country and may change over time. To facilitate international comparison of sound exposure records with commonly used values, this standard specifies an instrument that indicates sound exposure in square Pa-hours. If the manufacturer specifies a method for converting the indication into square Pa-hours, it is also permitted to use sound exposure indications in units other than square Pa-hours. For example, "dose" may be displayed as a specified value in square Pa-hours. The fraction or percentage of sound exposure in Pa-hours. The main application of personal sound exposure meters is to measure sound exposure near the head of a person, for example, to assess possible hearing loss according to standards such as ISO1999. The microphone of the personal sound exposure meter can be worn on the shoulder, collar, or other parts close to the ear. For many specific situations, such as in a factory, the sound incidence angle varies greatly during work, and the sound exposure indicated by the instrument worn on the human body may be different from the measurement value when the person is not present. When estimating the sound exposure when the person is not present, the influence of the human body wearing the personal sound exposure meter should be considered. 1 Scope
National Standard of the People's Republic of China
Technical Requirements for Personal Sound Exposure Meters
Specifications for personal souad exposure metersGB/T15952—1995
idt IEC 1252:1993
1.1 Sound exposure is a physical measurement of both the sound pressure and its duration at a given location, integrated over time by the square of the instantaneous frequency-weighted sound pressure.
1.2 This standard applies to instruments that measure A-weighted sound exposure to steady, intermittent, fluctuating, irregular or pulsed sound. Only instruments that meet the technical requirements of this standard are those that are worn on the human body to measure sound exposure. The measurement of workplace soundscape exposure is carried out in accordance with IS01999 and ISO9612 to determine occupational noise exposure.
1.3 This standard specifies the acoustic and electrical performance requirements of a personal sound exposure meter with one accuracy level. The corresponding accuracy level of the integrating sound level meter meets the Type 2 requirements of IF804:1985. And use A-weighted sound pressure level range of 80dB~-130dB, and nominal frequency range of 63Hz~8kHz.
1.4 The tolerance of the performance deviation of the instrument designed in accordance with the regulations represents the performance level of the instrument as a whole. The personal sound exposure meter is required to work within the tolerance of this standard under the specified range of environmental conditions. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB3240-82 Common frequencies in acoustic measurement bases GB3785-83 Electrical and acoustic properties and measurement methods of sound level meters GB/T 15173-94 Sound calibrator
TEC50 (801): 1984 International Electrotechnical Commission Chapter 801 Acoustics and electroacoustics IEC801-2: 1981 Electromagnetic compatibility of industrial process measurement and control equipment Part 2: Requirements for electrostatic discharge 1EC801-3: 1984 Electromagnetic compatibility of industrial process measurement and control equipment, Part 3: Requirements for radiated electromagnetic fields IEC804, 1995
Integrating-average sound level meter
ISO1683: 1983 Acoustics - Preferred reference quantities for sound levels ISO1999: 1990 Acoustics - Determination of occupational noise exposure and estimation of noise-induced hearing loss 3 Definitions
This standard shall use the following definitions. These definitions are consistent with the corresponding definitions in 1EC50 (801). 3.1 Sound exposure suundexposure
The time integral of the square of the instantaneous A-frequency-weighted sound pressure during the entire specified experience time, such as one working month. Note
Although the basic SI unit for sound exposure is quadratic Pa-second, for the measurement of sound exposure in the workplace, this standard still adopts the more convenient unit of quadratic Pa-hour.
The national technical system and
2 are expressed by symbols, A-weighted) sound pressure is GB/T 159521995
where (t) is the square of the instantaneous A-frequency-weighted sound pressure as a function of time:. If the A-weighted sound pressure Pa is Pascals and the action time is hour, the correct unit for sound exposure is quadratic Pa-hour. 3.2 Equivalent continuous A-weighted sound pressure level, time-averaged sound level equivalentcontinuaus A-weighed sound pressure level,time-average sound level
10 times the base 10 logarithm of the ratio of the time mean square of the A-frequency weighted sound pressure to the square of the reference sound pressure within the average time interval, dB.
1 is expressed symbolically. The equivalent continuous 4-weighted sound pressure level t, or the time-averaged sound level is given by the following formula: Laca.T = lolgt.-
pi(t)dr/pWww.bzxZ.net
wherein the action time: is expressed in the same units as the averaging time T, (t) is the instantaneous 4-weighted sound pressure in posts, which is the reference sound pressure of 20 micropermeters (20 xP) according to IS01683.
2 The relationship between the equivalent continuous A-weighted sound pressure level at an averaging time interval T and the total sound exposure occurring during this time is expressed as H -(p)2102*)
or alternatively as:
.AT ... IUlgE/(pT'))
where the time units used for sound exposure and averaging time are the same, 3.3 Normalized hourly average sound levelnormalizedgh-avoragcsoundlevel (3)
At the normalized time interval T, is the A-weighted time mean square level of sound during eight hours, d3, where the sound exposure is equal to the total sound exposure to time-varying sounds occurring at that point, not necessarily within the eight-hour interval. NOTE
1 The half-mean level (letter symbol) relative to the reference sound pressure and the normalized time interval T is given by the formula:
IA-9 = IOlg(E/t pT.J
2 For the convenience of calculation, for the sound exposure expressed in one-times-per-hour, substitute 20μPa, and substitute 8h into T, and the simplified normalized 8h average sound level d is as follows:
Lam.n - 101gtProvides a recommended method for testing the unipolar impulse response. 11 Self-latching overload indicators
11.1 A self-latching overload indicator shall provide an indication that the sound pressure level at the microphone has exceeded the upper limit of the specified sound level range. The overload indicator shall not operate above the commercial limit of the specified sound level range, but shall operate between the commercial limit and the upper limit of the specified sound level range (13) (peak level is 6 dB above the upper limit), and at all higher sound pressure levels with a duration of 4 or more. NOTE
1 The overload indicator may also operate when low-frequency high levels outside the range of the individual sound meter are present. 2 To prevent false overload indications, an exponential time constant of not more than 100% may be included in the overload indicator circuit: 11.2 Appendix 13 (Informative Appendix) describes recommendations for tests to demonstrate compliance with the requirements of this clause. 12 Sensitivity to Various Environments
12.1 General
If the sound exposure indicator is separated from the wearable part of the instrument, the entire personal sound exposure meter including the sensor shall comply with the requirements of this case and be used according to the manufacturer's recommendations. The microphone should be installed on the extension cable for normal use. Standard environmental conditions
12.2 Atmospheric pressure
GB/T15952—1995
For standard atmospheric pressure changes of ±10%, the sound exposure indication of the standard sound pressure level at a frequency of 1kHz and the reference integration time shall not vary by more than -11% to +12% of the sound exposure indication at an atmospheric pressure of 101.3kPa. 12.3 Air temperature
For ambient air temperature changes of at least 0°C to 40°C, the sound exposure indication of the reference pressure level at a frequency of 1kHz and the reference integration time shall not vary by more than -11% to +12% of the sound exposure indication at an air temperature of 20°C. The nominal relative humidity during the test shall be indicated.
12.4 Relative humidity
For humidity changes of at least 30% to 90%, the sound exposure indication of the reference sound pressure level at a frequency of 1 kHz and a reference integration time shall not vary by more than -11% to +12% of the sound exposure indication at a relative humidity of 6%. The test shall be conducted at a temperature of 10°C.
12.5 Magnetic field
The manual shall state that the microphone of the personal sound exposure meter is replaced by an equivalent electrical impedance and, if applicable, that the instrument is placed in a uniform magnetic field with a test frequency of at least (50±1) Hz or (60±1) Hz and a strength of 80 A/m. After an integration time of 1 h, the sound exposure indication in the direction of maximum response is taken. The manufacturer shall indicate both the frequency and direction and shall also specify the structure of the microphone extension circuit. 12.6 Radio frequency electromagnetic field
The influence of radio frequency electromagnetic field on the performance of the personal sound exposure meter shall be minimized as much as possible. The user's manual shall state the limits for using the personal sound exposure meter near sources of electromagnetic field radiation.
Note: The manufacturer shall determine the effects of radio frequency electromagnetic fields in accordance with IEC8013. 12.7 Electrostatic discharge
The effects of electrostatic discharge on the performance of the personal sound exposure meter shall be minimized. The user's manual shall state the limits for using the personal sound exposure meter near sources of electrostatic discharge.
Note: The manufacturer shall determine the effects of electrostatic discharge in accordance with IFC 8012. 12.8 Mechanical vibration
The effects of mechanical vibration on the performance of the personal sound exposure meter shall be minimized. The user's manual shall state the limits caused by mechanical vibration. 13 Instrument marking
13.1 If practicable, the name of the display unit (sound exposure) and its unit or its association shall appear in or near the indicator. If this marking is not practicable, the user's manual shall describe the method for determining the sound exposure. For example, the nameplate may be marked with "sound exposure meter" and the indicator with "Pa\H". If the symbol is a percentage indication, the sound exposure should also be expressed as the 3rd power Pa-hour corresponding to 100%. For example, 100% corresponds to a normalized 8-hour average sound level of 90 rB, then 3.2 Pah-100%. 13.2 Personal sound exposure meters that meet all the technical requirements of this standard should be marked with GB/T15952-1995. The manufacturer's name, model and serial number should also be confirmed.
14 User Manual
Each personal sound exposure meter shall be provided with an instruction manual which shall contain at least the following information: a) recommendations for mounting the personal sound exposure meter on the wearer (including the microphone if separate); h) a description of the displayed quantity and, if the sound exposure meter does not use sub-Pa-hours as the unit of sound exposure, a detailed description including the analysis formula for converting the displayed sound intensity to sub-Pa-hours; the sound exposure range and level range required for the specified model of personal sound exposure meter to meet the requirements of this standard; d) the sound pressure level within the specified tolerance within the frequency range of the personal sound exposure meter; e) the frequency response; The response extends to the frequency range within which the tolerance can be maintained when it is below 63 Hz or above BkHz: gate
g) The reference frequency is 1 kHz!
GB/T15952—1995
h) Reference sound pressure level, reference integration time, reference sound exposure; i) Description of the recommended procedure: (1) Verify the sensitivity of the personal sound exposure meter according to Article 6.1: (2) Calibrate the absolute acoustic sensitivity of 1 kHz according to Article 6.2
i) Description of the recommended microphone for measuring the relative frequency response according to Article 7.1:) After input test setup (input test point, specified impedance Recommended method for inserting an electrical signal through a microphone dummy head, or equivalent input adapter, and measuring the voltage at an optional electrical output test point: 1) The connecting electrical impedance at each test point provided to provide negligible error in the indicated sound exposure: m) The free-field relative frequency response characteristics in the reference direction for a typical microphone and installed as recommended by the manufacturer; n) An explanation of the typical percentage deviation of the indicated sound exposure in response to positive and negative monopolar pulses in accordance with Chapter 10; 0) The operating ranges of atmospheric pressure, ambient air temperature, and relative humidity in accordance with Clauses 12.2, 12.3, and 12.4; ) The ambient air temperature for long-term storage q) the influence of alternating magnetic fields according to clause 12.5; r) the exposure of the instrument to radio frequency electromagnetic fields according to clauses 12.6, 12.7 and 12.8, if applicable; t) a description of the performance limits of electrostatic discharge sources or mechanical vibration; s) the expected and corresponding nominal life of the personal sound exposure meter from fully charged operation for applicable battery models; t) a description of the recommended method for verifying the battery voltage supply; u) the recommended time interval for periodic testing to verify the acoustic and electrical characteristics of the personal sound exposure meter; and v) recommendations for test procedures and test equipment to verify compliance with the technical specifications of this standard. In particular, when the structure of the personal sound exposure meter is not convenient for direct connection to external test equipment, the manufacturer should provide recommended methods for appropriate use of acoustic or other test signals. E
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GB/T 15952—1995
Appendix A
(Suggestive Appendix)
Sound exposure and corresponding normalized 8 h average sound level Table A Sound exposure and corresponding normalized 8 h average sound level: Lha-bha
Note: For the normalized 8 h average sound level in dB, the sound exposure E in Pa-hour can be calculated by the following formula: E=PTC10×.Bh)
Where P,=20 μPa, normalized time T,-8 h, can be seen in formula (5). Appendix B
(Suggestive Appendix)
Recommended test B1 Starting procedure for verifying the performance of personal sound exposure meters
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