UNE-EN IEC 60942:2018

This International Standard specifies the performance requirements for three classes of sound

calibrator: class LS (Laboratory Standard), class 1 and class 2. Acceptance limits are smallest

for class LS and greatest for class 2 instruments. Class LS sound calibrators are normally used

only in the laboratory; class 1 and class 2 are considered as sound calibrators for field use.

A class 1 sound calibrator is primarily intended for use with a class 1 sound level meter and a

class 2 sound calibrator primarily with a class 2 sound level meter, as specified in IEC 61672-1.

The acceptance limits for class LS sound calibrators are based on the use of a laboratory

standard microphone, as specified in IEC 61094-1, for demonstrations of conformance to the

requirements of this International Standard. The acceptance limits for class 1 and class 2

sound calibrators are based on the use of a working standard microphone, as specified in

IEC 61094-4, for demonstrations of conformance to the requirements of this International

Standard.

To promote consistency of testing of sound calibrators and ease of use, this International

Standard contains three normative Annexes - Annex A Pattern evaluation tests , Annex B

Periodic tests , Annex C Pattern evaluation report , and two informative Annexes - Annex D

Relationship between tolerance interval, corresponding acceptance interval and the maximum

permitted uncertainty of measurement and Annex E Example assessments of conformance to

specifications of this International Standard .

This International Standard does not include requirements for equivalent free-field or random201

incidence sound pressure levels, such as can be used in the overall sensitivity adjustment of a

sound level meter.

A sound calibrator may provide other functions, for example, tonebursts. Requirements for

these other functions are not included in this International Standard.