Tc Sensor Maintenance; Maintenance Schedule; Testing The Sensor Condition; Membrane Replacement - Hach ORBISPHERE 51 Series User Manual

4. Turn the tool clockwise to screw in the new sensor
15.3

TC sensor maintenance

Carry out the maintenance in a clean dry place in order to avoid damaging the sensor's
precision components, and also to prevent water or humidity from getting into the sensor.

15.3.1 Maintenance schedule

Service includes membrane replacement and external cleaning to restore the original sensor
sensitivity. This means low running costs and down time reduced to a minimum.
The membrane needs to be replaced once or twice a year depending on application conditions.
This can be tailored accordingly.
Note: If you are not familiar with ORBISPHERE sensor servicing, your Hach representative will be glad to
assist you

15.3.2 Testing the sensor condition

Periodically, inspect visually the sensor head for any deposits. Rinse it under clean tap water,
and dry with a clean tissue.
To verify the sensor, check measurements vs. a known standard sample value:
• If reading deviation is ±1% of the expected value, no action needs to be taken.
• If deviation exceeds ± 1%, perform a new calibration.
• If deviation exceeds 10% of the original values, replace the membrane.

15.3.3 Membrane replacement

To remove the membrane, follow the steps below:
1. Place the thermal conductivity sensor vertical with the head up. Remove the plastic storage
cap.
2. Unscrew the protection cap, using the tool provided in the maintenance kit.
Never remove the protection cap, unless you plan to replace the membrane.
3. Pay attention to the components inside the protection cap. Refer to
caps and related part kits on page
Note: The illustration is an example only. Your configuration may differ.
4. Pull up the membrane holding ring with the tool provided in the maintenance kit. Remove
membrane(s).
Note: For correct membrane selection. Refer to
spot, finger tight. Do not overtighten. Once secure,
pull off the maintenance tool.
Maintenance and Troubleshooting
N O T I C E
C A U T I O N
113. Note the assembly order of each item.
TC sensor on page 14.
TC sensor protection
105