DIN EN 60942:2004-05

This International Standard specifies the performance requirements for three classes of sound calibrator: laboratory standard (class LS), class 1 and class 2. Tolerance 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. Revision of the IEC standard of 1997-11 provides correct consideration of the measurement uncertainty of the testing laboratory and contains additional requirements concerning EMC.