Castle Group Ltd

In the British and international standards for sound level meters, the accuracy and performance of an instrument is defined by its type. The classification runs from Class 0 to Class 3 with 0 being the most accurate and demanding and Class 3 being the least.

Classes 1 and 2 are most applicable for user applications with Class 1 being the recommended for professionals in the field. Class 0 is a requirement for laboratory environments.

Class 3 meters should only be considered for spot inspections and general checks.

Sound level meters should all conform to a specific standard depending on the type of meter and the Class requirement. Non integrating meters are covered in IEC 60651, Integrating Sound Level Meters in IEC 60804.