This standard covers the various types and classes of cold water compound type meters in sizes 2 in. (50 mm) through 8 in (200 mm) and the materials and workmanship used in their fabrication. Compound meters shall consist of a combination of a main line meter of the turbine type for measuring high rates of flow and a bypass meter of appropriate size for measuring low rates of flow. The compound meter shall have an automatic valve mechanism for diverting low rates of flow through the bypass meter.

Major revisions to this edition of the standard include the following:

1. Class I compound meters have been removed from the standard
2. Information is included on lead content criteeral and the new NSF/ASI Standard 372, Drinking Water System Components-Lead Content, as well as on recent legislation revising the definition of "lead free."
3. The definition of "manufacturer" has been changed.
4. Stainless steel has been added as a material for several meter components.
5. More details are included on the requirements for electronic display registers.