User Guide

Instruction Manual DO 100
41
9.4 Membrane/O-ring Replacement (Optional Procedure)
It is recommended only experienced service personnel can perform this procedure.
This procedure is OPTIONAL, and should only be performed if you have new membrane and
O-ring. You are also required to have a membrane installation tool. These items are available
as optional accessories in the “Accessories” section.
1. Pull off the probe guard. See Figure 34.
2. Unscrew the membrane cap from the probe.
3. Hold the probe under hot running water and brush
away the white oxide on the cylindrical anode with a
stiff plastic brush – do not use metal cleaning
material.
4. If the cathode has any deposits, remove them with a
light scouring powder. Do not polish the cathode.
5. Using the installation tool, unscrew and remove the
membrane lock from the membrane cap. See Figure
35 on the following page.
6. Remove the membrane and O-ring. Discard both.
7. Rinse the membrane cap and membrane lock in tap
water.
8. Install a new O-ring inside the membrane cap.
9. Install a new membrane. Make sure the membrane
covers the O-ring all around its circumference. See
Figure 36 on the following page.
Figure 34: Positioning of O-ring
& membrane