Hach ORBISPHERE 31290TC Manuel D'utilisation Simplifié page 13

7.3 Membrane replacement
7.3.1 Removing the membrane
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. Note the assembly order of each item.
4. Pull up the membrane holding ring with the tool provided in the maintenance kit. The membrane
holding ring comes in two slightly different internal diameters, depending on the membrane(s)
total thickness. Remove membrane(s).
7.3.2 Installing the membrane
1. The membrane mounting surface must be clean and even. Replace the membrane O-ring on the
sensor head with a new one.
Note: The 29039.0 Nitril O-ring can be reused if it is still in good condition. Membrane O-rings are part of the
protection cap kit.
2. 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.
3. Take a few membranes out of the storage box. Using tweezers included in the kit, pick up one
membrane from the stack, and gently place it on the sensor tip. Make sure it is centered
Note: Distinguish the membrane from the protection paper:
• The membrane is transparent (translucent).
• The protection paper is opaque.
C A U T I O N
English 13