What volume of filling solution should be dispensed into the ISENH3181 membrane module when replacing the membrane?

Document ID

Document ID TE2792

Published Date

Published Date 06/06/2018
Question
What volume of filling solution should be dispensed into the ISENH3181 membrane module when replacing the membrane?
Summary
Membrane filling solution volume.
Answer
The fill solution used for the ISENH3181 membrane module is 0.1 M NH4Cl. No more than 0.5 mL or 12 drops from the Hach fill solution bottle (Catalog Number 4447226) should be used. Overfilling the membrane module can create a leak path between the membrane module o‐ring and the probe body. This can lead to stabilization issues and long response times.

NOTE: this is a different recommendation than stated in the manual of the Hach sensION ammonia ISE, where excess fill solution and overfill of the membrane module were acceptable. Excessive filling of the membrane module can be problematic for the IntelliCAL ISENH3181 Ammonia ISE.