In-Situ Clark Cell Maintenance Kit for the TROLL 9500 Instrument - Manual

Instruction Sheet
Multi-Parameter
Water Quality TROLL ®
(over)
TIP: Try to eliminate air bubbles. Tapping the side of the module
briskly with your fingernail is helpful.
Ensure the membrane does not leak. You should not see any
drops on the surface. There should be no visible air bubbles.
DISSOLVED OXYGEN (DO)
SENSOR SERVICE KIT
Catalog No. 33200 (1 mil), 33440 (2 mil)
Membrane
Dissolved
Oxygen
Sensor
Cathode
MEMBRANE
MODULE
Anode
o-rings
Cap
The polarographic (Clark cell) DO sensor performs best in clean water. In
environments with high organic content, the membrane can become fouled.
Rips, tears and other damage will also affect membrane performance. For best
results, replace the membrane when the slope and offset calculated during
calibration change dramatically, and also after a long-term deployment.
DESCRIPTION
The DO service kit contains:
• Membrane modules (5)
• O-rings (10) and o-ring lubricant
• DO electrode filling solution (potassium chloride, KCl)
• Ammonia cleaning solution and brush
• Polishing strips
REPLACING THE MEMBRANE MODULE
1. Remove any moisture or dirt from the area around port 2, then use the
sensor removal tool to remove the DO sensor. Remove and discard the
used membrane module.
2. Inspect the sensor for discoloration due to silver chloride (AgCl) deposition.
If the sensor appears to be excessively discolored from its original matte
grey color, clean the anode with ammonia and a soft brush. Buff the
cathode with a polishing strip. Rinse well and shake dry.
3. Remove the protective cap from a new membrane module.
4. Holding the membrane module open-end up, position the dispenser of the
filling solution bottle against the side and slowly fill the module.
5. Insert the sensor into the open end of the membrane module. To minimize
air, electrolyte should overflow from the open end as the sensor is inserted.
6. Thread the membrane module onto the sensor.
7. Install and condition the sensor as described next.