Hach-Lange HQD - Gel filled ORP_Redox electrode MTC - Manual (Page 9)

DOC272.53.80033 9
Maintenance
Clean the probe if the response time becomes slow ( Clean the probe on page 9 ).
Storage
Note: For optimal performance, the reference junction must not dry out.
Short-term storage:
Store the electrode in Hach Electrode Storage Solution or 3M potassium chloride
(KCl) solution. The electrode can also be stored for up to 2 hours in a sample (if the
sample pH is not extreme).
Long-term storage:
1. Rinse the electrode with deionized water. Dry the electrode with a lint-free cloth.
2. Fill the electrode storage cap halfway with Hach Electrode Storage Solution or 3M
potassium chloride (KCl) solution.
3. Install the electrode storage cap. Make sure that the storage cap covers the reference
junction completely.
Rugged probe maintenance
The shroud protects the sensor elements during rugged applications. Damage to the
sensing elements can occur if the shroud is not installed during field use. Damage under
these conditions is not covered under warranty.
To remove the shroud:
1. Unscrew the locking ring and slide the shroud and locking ring off the probe.
2. Slide the shroud and locking ring off the probe.
To install the shroud
1. Place the locking ring on the probe body with the threads toward the platinum disc.
2. Slide the shroud on the probe until it is seated in the locking groove.
3. Hand-tighten the locking-ring on the shroud.
Clean the probe
For general cleaning (including oils, greases, and organics):
• Rinse the electrode with deionized water and blot dry with a lint-free cloth.
• Immerse the sensor array and platinum disc in Electrode Cleaning Solution or
warm detergent solution for up to 15 minutes.
Note: The platinum disc can be polished using a soft cloth or cotton swab with detergent
solution.
• Rinse the electrode sensor array and platinum disc with deionized water. Blot dry
with a lint-free cloth.
For inorganic deposits
• Immerse the platinum disc in a solution of 0.1M hydrochloric or nitric acid solution
and soak for up to 15 minutes.
• Rinse the electrode sensor array and platinum disc with deionized water. Blot dry
with a lint-free cloth.
After cleaning has been performed, condition the platinum electrode in
representative sample prior to use.