IEC 61672-1:2002 pdf download

IEC 61672-1:2002 pdf download.Electroacoustics -sound level meters -Part 1: Specifications.
3.16
reference sound pressure level
sound pressure level specified for testing the electroacoustical performance of a sound level meter
NOTE Reference sound pressure level is expressed in decibels (dB).
3.17
reference level range
level range specified for testing the electroacoustical characteristics of a sound level meter and containing the reference sound pressure level
NOTE Reference level range is expressed in decibels (dB).
3.18
calibration check frequency
nominal frequency, in the range from 160 Hz to 1 250 Hz, of the sinusoidal sound pressure produced by a sound calibrator that is used in checking and adjusting a sound level meter
3.19
level linearity error
at a stated frequency, an indicated signal level minus the anticipated signal level
NOTE Level linearity error is expressed in decibels (dB).
3.20
linear operating range
on any level range and at a stated frequency, the range of sound levels over which level linearity errors are within the tolerance limits specified in this standard
NOTE Linear operating range is expressed in decibels (dB).
3.21
total range
range of A-weighted sound levels, in response to sinusoidal signals, from the smallest sound level, on the most-sensitive level range, to the highest sound level, on the least-sensitive level range, that can be measured without indication of overload or under-range and within the tolerance limits specified in this standard for level linearity error
NOTE Total range is expressed in decibels (dB).
3.22
toneburst
one or more complete cycles of a sinusoidal signal starting and stopping at a zero crossing of the waveform
3.23
toneburst response
maximum time-weighted sound level, time-average sound level, or sound exposure level, measured in response to a sinusoidal electrical toneburst minus the corresponding measured sound level of the steady sinusoidal input signal from which the toneburst was extracted
NOTE Toneburst response is expressed in decibels (dB).
3.24
reference orientation
orientation of a sound level meter for tests to demonstrate conformance to the specifications of this standard for emissions of, and susceptibility to, radio frequency fields
4 Reference environmental conditions
Reference environmental conditions for specifying the performance of a sound level meter are:
— air temperature 23 °C;
— static pressure 101,325 kPa;
— relative humidity 50 %.
5 Performance specifications
5.1 General
5.1.1 Generally, a sound level meter is a combination of a microphone, a signal processor, and a display device.
The signal processor includes the combined functions of an amplifier with a specified and controlled frequency response, a device to form the square of the frequency-weighted time- varying sound pressure, and a time integrator or time averager. Signal processing that is necessary to conform to the specifications of this standard is an integral part of a sound level meter.
In this standard, a display device provides either a physical and visible display, or storage, of measurement results. Any stored measurement result shall be available for display by means of a manufacturer-specified device, for instance a computer with associated software.
5.1.2 The performance specifications of this clause apply under the reference environmental conditions of clause 4.
5.1.3 For specifying the emission of, and susceptibility to, radio frequency fields, sound level meters are classified into three groups as follows:
— group X sound level meters: self-contained instruments that include sound level measurement facilities according to this standard and which specify internal battery power for the normal mode of operation, requiring no external connections to other apparatus to measure sound levels;
— group Y sound level meters: self-contained instruments that include sound level measurement facilities according to this standard and which specify connection to a public supply of electric power for the normal mode of operation, requiring no external connections to other apparatus to measure sound levels; and
— group Z sound level meters: instruments that include sound level measurement facilities according to this standard and which require two or more items of equipment, which are essential constituent parts of the sound level meter, to be connected together by some means for the normal mode of operation. The separate items may be operated from internal batteries or from a public supply of electric power.