Hach-Lange ORBISPHERE 31xxx Basic User Manual User Manual

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1. Install the membrane support with the groove on the upper side.

Note: The membrane support is individually machined and paired with the sensor. Therefore make sure that
the correct membrane support is used on the correct sensor.

2. Insert the prongs of the membrane support removal tool into the membrane support holes.
3. Tighten the membrane support finger tight.

C A U T I O N

Too much torque will damage the sensor electrodes.

4. The membrane mounting surface must be clean and even. Replace the membrane O-ring on the

sensor head with a new one.

Note: The 29039.4 Nitril O-ring can be reused if it is still in good condition. Membrane O-rings are part of the
protection cap kit.

5. Using the syringe or bottle nozzle included in the maintenance kit, fill up the sensor cavity with

electrolyte. Be careful not to touch the electrodes with the needle, as a scratch on the surface
may lead to loss of performance. Tilt the sensor slightly and inject into the lower hole, pushing
bubbles out at the upper hole. Gently tap on the sensor side to move trapped bubbles. Return the
sensor to the vertical position. The last drop of electrolyte should form a cupola on top of the
sensor tip.

6. In the maintenance kit, pick up the two part membrane mounting tool. Install the sleeve over the

sensor head (end with shoulder downwards).

Note: Once installed, a membrane cannot be reused. Avoid touching the membrane with bare fingers, as this
may affect its sensitivity.

7. Take a few membranes out of the storage box. Using tweezers included in the kit, pick up one

membrane of the stack, and gently place it on the sensor tip. Make sure it is centered, and no
bubble is trapped. If a sensor mask is used, place it directly on top of the membrane. The
membrane diameter is larger than sensor head diameter. This is normal, as the membrane will
fold over the sensor tip.

Note: Distinguish the membrane from the protection paper:

• The membrane is transparent (translucent).

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