How can accuracy be verified when using the High Range plus Chemical Oxygen Demand (HR+ COD) reagents?

Document ID

Document ID TE240

Published Date

Published Date 27/05/2017
Question
How can accuracy be verified when using the High Range plus Chemical Oxygen Demand (HR+ COD) reagents?
Summary
Accuracy check standard for HR+ COD
Answer
Currently, Hach offers COD standards of 300 mg/L, 800 mg/L, or 1000 mg/L, which do not fit into the HR+ range. Standards can be prepared by the user with dry KHP; however making this is not user friendly for many people.

Another option is to use a 4L bottle of a 5000 mg/L Total Organic Carbon (TOC) standard (Catalog Number/Order Code 5847400).  It is made from KHP and should give a result of 12,650 mg/L COD.