Emerson Rosemount TCL - Total Chlorine Sensor

12.2 Total chlorine sensor
12.2.1 General
When used in clean water, the sensor requires little maintenance. Generally, the sensor
needs maintenance when the response becomes sluggish or noisy or when readings drift
following calibration.
Maintenance frequency is best determined by experience.
12.2.2 Cleaning the membrane
Keep the membrane clean.
Clean the membrane with water sprayed from a wash bottle. Use a soft tissue to gently
wipe the membrane.
12.2.3 Replacing the membrane
Complete the following steps to replace the membrane on the total chlorine sensor.
Procedure
1. Hold the sensor with the membrane facing up.
2. Unscrew the membrane retainer. Remove the membrane assembly and O-ring.
See Figure.
3. Inspect the cathode. If it is tarnished, clean it by gently rubbing in the direction of
the existing scratches (do not use a circular motion) with 400-600 grit silicon carbon
finishing paper. Rinse the cathode thoroughly with water.
4. Prepare a new membrane. Hold the membrane assembly with the cup formed
by the membrane and membrane holder pointing up. Fill the cup with electrolyte
solution. Set aside.
5. Put a new O-ring in the groove.
6. Place a drop of electolyte solution on the cathode. Invert the membrane assembly
and place it over the cathode stem.
7. Screw the membrane retainer back in place.
8. Hold the sensor with the membrane pointing down. Shake the sensor a few times,
as though shaking down a clinical thermometer.
12.2.4 Replacing the electrolyte solution and membrane
Procedure
1. Unscrew the membrane retainer.
2. Remove the membrane assembly and O-ring.
See .
3. Hold the sensor over a container with the cathode pointing down.
4. Remove the fill plug.
5. Allow the electrolyte solution to drain out.
6. Wrap the plug with
Reference Manual Maintenance
00809-0200-3415 January2023
Rosemount TCL 56 53