The DR1900 came with an adapter B (1 inch round double path cells), how is this used?
DR1900 adapter B
This adapter was provided to assist customers with the obsolete spectrophotometer DR2010 flow through cell. The adapter C would be used for the more common double path cell catalog number 4864302. If an adapter is required it is included in the instrument-specific information for reagent addition table at the beginning of the Hach procedure.