User Guide

PROBE MAINTENANCE & CLEANING

The probe can be compensated for normal contamination by a process of

re-calibration. However, it is recommended that the process conductivity

probe be removed from the system regularly for maintenance.

For HI7635 only: Deposits on the conductivity probe can be removed by

immersing the probe in 0.1 N Hydrochloric acid for about 30 minutes.

Heavier deposits may demand longer immersion periods. Clean the

electrode thoroughly with water prior to the reinstallation. On reinstalling,

check the seals carefully to ensure that a leak connection is obtained.

For HI7638 only: Rinse the probe with tap water. If a more thorough

cleaning is desired, unscrew the Ultem sleeve and clean the sensors with

a nonabrasive cloth or alcohol.

After cleaning the probe, re-calibrate the instrument. However, if the

instrument will not re-calibrate with the clean probe, you must replace the

probe.

Note: Always re-calibrate the meter when attaching a new probe.