DR300_Chlorine Standard Prep Claros Enabled App Note
The Hach DR300 Pocket Colorimeter contains built-in calibration curves for free and total chlorine using the USEPA DPD method (reference methods Hach Methods 8021 and 8167). This document describes how to prepare free chlorine standards suitable for verification of built-in calibration curves, and how to verify the calibration through the range 0.02-8.0 mg/L as Cl2. These curves are divided into two ranges and two methods. The low range method is calibrated from 0.02-2.0 mg/L Cl2. The high range method is calibrated from 0.1-8.0 mg/L Cl2. Calibration verification standard concentrations must fall within these calibrated ranges. Multiple standard concentrations may be prepared using this procedure depending on the regulatory and quality control needs of the individual laboratory.