Thermo Fisher Scientific CyberScan DO 300 - Manual (Page 41)

Instruction Manual DO 300
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9.2 Membrane Housing Replacement
Replacement of the membrane cap housing/ membrane is
required only when you cannot calibrate the probe, or if the
membrane is damaged.
Typical membrane damages are punctures or wrinkles
caused during measurements or cleaning.
Your new DO probe comes with a replacement membrane
housing. To order more replacement membrane housing ,
see the “Accessories” section on page 47 - 48.
9.2.1 To replace the membrane cap (with pre-
installed membrane)
Replacement is much easier with single membrane housing.
Simply unscrew the old membrane cap housing, add solution
to the new housing, and screw the new cap housing in place.
1. Fill the membrane cap housing with electrolyte solution
and inspect the bottom for leaks. If the solution drops
are leaking from the membrane, use a new cap housing.
2. If the assembly is leak-free, fill the membrane cap
housing with electrolyte to the brim.
3. Tap the side of the housing gently to remove any air
bubble that may be sticking to the membrane.
4. Screw the cap onto the probe. Excess electrolyte will
drain out.
5. Replace probe guard.
6. Calibrate the probe (see section 4) after the %
saturation readings have stabilised.
Figure 34: Positioning of O-ring
& membrane