This document specifies the performance requirements for three classes of sound calibrator:class LS(LaboratoryStandard),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 soundcalibrator primarily with a class 2sound level meter, as specified in IEC 61672-1.
