Can hardness levels effect the functionality of the CL17 analyser?

Document ID

Document ID TE5506

Published Date

Published Date 21/01/2019
Question
Can hardness levels effect the functionality of the CL17 analyser?
Summary
Hardness levels affecting the CL17 analyser's performance.
Answer
The CL17 DPD chemistry is not affected by hardness levels up to 1000 mg/L CaCO3, although there are Cl17's installed on treated cooling waters that have total hardness levels less than 5000 mg/L. The sample alkalinity must be below 400 mg/L CaCO3 for the Free Chlorine CL17 and 700 mg/L CaCO3 for the Total Chlorine CL17. One quick way to check if the analyser can tolerate the sample alkalinity is to add 1 mL each of Indicator and Buffer to approximately 80-mL sample, mix and check the pH. For the Free CL17, the final pH should be between 6.3-6.7 and for Total CL17 between 5.0-5.5 pH.