The purpose of this standard is to provide the minimum requirements for operation and maintenance of online turbidimeters. This standard may be referenced in documents for purchasing online turbidimeters, may be used as a guide for verifying the accuracy and precision of online turbidimeters, and may assist utilities in establishing online turbidimeter O&M procedures. The user should ensure the environmental conditions of the application match the manufacturer-specified conditions and requirements for the analyzer. The stipulations of this standard apply when this document has been referenced and then only to online turbidimeters used in the treatment and monitoring of potable water, reclaimed water, or wastewater effluent.