IEC 61252 pdf download – Electroacoustics – Specifications for personal sound exposure meters

IEC 61252 pdf download – Electroacoustics – Specifications for personal sound exposure meters
1.1Sound exposure is a physical measure that accounts for both the sound pressure and itsduration, at a given location，through an integral-over-time of the square of instantaneousfrequency-weighted sound pressure.
1.2This International Standard is applicable to instruments for measurement of A-frequency-weighted sound exposure resulting from steady, intermittent, fluctuating, irregular, or impulsivesounds. Instruments complying with the specifications of this International Standard areintended to be worn on a person to measure sound exposure.Measurements of soundexposure in the workplace may be useful for determinations of occupational noise exposure, inaccordance with lsO1999 and lso 9612.
1.3 This lnternational Standard specifies acoustical and electrical performance requirementsfor personal sound exposure meters of one accuracy grade.The accuracy grade correspondsto that for an integrating sound level meter which complies with the Type 2 requirements ofIEC 60804 for an A-weighted sound pressure level range from 80 dB to 130 dB and a nominalfrequency range from 63 Hz to 8 kHz.
1.4Tolerances on deviations of an instrument’s performance from specified design goalsrepresent the performance capabilities of practical instruments.Personal sound exposuremeters are required to operate within the tolerances of this International Standard overspecified ranges of environmental conditions.
2Normative references
The following normative documents contain provisions which，through reference in this text,constitute provisions of this International Standard.At the time of publication，the editionsindicated were valid. All normative documents are subject to revision， and parties toagreements based on this lnternational Standard are encouraged to investigate the possibilityof applying the most recent editions of the normative documents listed below.Members of lEcand lso maintain registers of currently valid normative documents.
lEC 60050(801):1984，Advance edition of the International Electrotechnical Vocabulary,Chapter 8oi,Acoustics and electroacoustics
IEC 60651:1979,sound level meters
IEC 60801-2:1984，Electromagnetic compatibility for industrial-process measurement andcontrol equipment – Part 2: Electrostatic discharge requirements
IEC 60801-3:1984，Electromagnetic compatibility for industrial-process measurement andcontrol equipment – Part 3: Radiated electromagnetic field requirements
IEC 60804:1985,Integrating-averaging sound level meterslEC 60942:1988,Sound calibrators
IEC 61000-4-2:1995,Electromagnetic compatibility (EMC) – Part 4:Testing and measurementtechniques – Section 2: Electrostatic discharge immunity test. Basic EMC publication
IEC 61000-4-3:1995,Electromagnetic compatibility (EMC) – Part 4:Testing and measurementtechniques – Section 3:Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-6-1:1997，Electromagnetic compatibility(EMC) – Part 6: Generic standards -Section 1: lmmunity for residential, commercial and light-industrial environments
IEC 61000-6-2:1999，Electromagnetic compatibility (EMC) – Part 6-2: Generic standards -Immunity for industrial environments
CISPR 22:1997, Information technology equipment – Radio disturbance characteristics – Limitsand methods of measurement
CISPR 61000-6-3:1996，Electromagnetic compatibility (EMC) – Part 6: Generic standards -Section 3: Emission standard for residential, commercial and light-industrial environments
Iso 266:1975,Acoustics – Preferred frequencies for measurements
ISO 1683:1983,Acoustics – Preferred reference quantities for acoustic levels
ISo 1999:1990，Acoustics – Determination of occupational noise exposure and estimation ofnoise-induced hearing impairment
Iso 9612:199X，Acoustics – Guidelines for the measurement and assessment of exposure tonoise in the working environment ”
3Definitions
For the purposes of this International Standard, the following definitions apply. Definitions areconsistent with corresponding definitions in lEc 60050(801).
3.1
sound exposure
time integral of squared, instantaneous A-frequency-weighted sound pressure over a specifiedevent, for example, a working day
NOTE 1 Although the primary sl unit for sound exposure is the pascal-squared second，for measurements ofsound exposure in the workplace， the more-convenient derived unit，the pascal-squared hour， is used in thislnternational Standard.
NOTE 2 In symbols，(A-weighted) sound exposure is
E.o2(t)d t
(1)
where pA2(t) is the square of instantaneous A-frequency-weighted sound pressure as a function of time t for anintegration time period starting at t and ending at ty. The unit of sound exposure E is pascal-squared hours ifA-weighted sound pressure p; is in pascals and the running time t in hours.