BS EN 61672-1:2013

INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Reference environmental conditions
5 Performance specifications
6 Environmental, electrostatic, and radio-frequency
  requirements
7 Provision for use with auxiliary devices
8 Marking
9 Instruction Manual
Annex A (informative) - Relationship between tolerance
        interval, corresponding acceptance interval and
        the maximum-permitted uncertainty of
        measurement
Annex B (normative) - Maximum-permitted uncertainties
        of measurement
Annex C (informative) - Example assessments of
        conformance to specifications of this
        standard
Annex D (normative) - Frequencies at fractional-octave
        intervals
Annex E (normative) - Analytical expressions for
        frequency-weightings C, A, and Z
Annex ZA (normative) - Normative references to
         international publications with their
         corresponding European publications

Provides electroacoustical performance specifications for three kinds of sound measuring instruments: - a time-weighting sound level meter that measures exponential-time-weighted, frequency-weighted sound levels; - an integrating-averaging sound level meter that measures time-averaged, frequency-weighted sound levels; and - an integrating sound level meter that measures frequency-weighted sound exposure levels.

IEC 61672-1:2013 gives electroacoustical performance specifications for three kinds of sound measuring instruments:
- time-weighting sound level meters that measure exponential-time-weighted, frequency-weighted sound levels;
- integrating-averaging sound level meters that measure time-averaged, frequency-weighted sound levels; and
- integrating sound level meters that measure frequency-weighted sound exposure levels. Sound level meters specified in this standard are intended to measure sounds generally in the range of human hearing. Two performance categories, class 1 and class 2, are specified in this standard. Acceptance limits for class 2 are greater than, or equal to, those for class 1. This standard is applicable to a range of designs for sound level meters. A sound level meter may be a self-contained hand-held instrument with an attached microphone and a built-in display device. A sound level meter may be comprised of separate components in one or more enclosures and may be capable of displaying a variety of acoustical signal levels. Sound level meters may include extensive analogue or digital signal processing, separately or in combination, with multiple analogue and digital outputs. Sound level meters may include general-purpose computers, recorders, printers, and other devices that form a necessary part of the complete instrument. Sound level meters may be designed for use with an operator present or for automatic and continuous measurements of sound level without an operator present. Specifications in this standard for the response to sound waves apply without an operator present in the sound field. This second edition cancels and replaces the first edition published in 2002. It constitutes a technical revision. In this second edition, conformance to specifications is demonstrated when measured deviations from design goals do not exceed the applicable acceptance limits, and when the uncertainty of measurement does not exceed the corresponding maximum-permitted uncertainty, with both uncertainties determined for a coverage probability of 95 %.