User Guide

18
• Make sure that the rubber O-ring is seated
properly inside the membrane cap.
• With the sensor facing down, screw the
membrane cap clockwise. Some electro-
lyte will overflow.
The Platinum cathode (#8 in the Functional
Description at page 2) should always be bright
and untarnished. If it is tarnished or stained,
which could be due to contact with certain
gases or extended use with a loose or dam-
aged membrane, the cathode should be
cleaned. You can use a clean lint-free card-
board or cloth. Rub the cathode very gently
side to side 4-5 times. This will be enough to
polish and remove any stains without dam-
aging the platinum tip. Afterwards, rinse the
probe with deionized or distilled water and
install a new membrane cap using fresh elec-
trolyte and follow the steps above. Recalibrate
the instrument.
Important: in order to have accurate and
stable measurements, it is important that the
surface of the membrane is in perfect condi-
tion. This semipermeable membrane isolates
the sensor elements from the environment
but allows oxygen to enter. If any dirt is
observed on the membrane, rinse carefully
with distilled or deionized water. If any imper-
fections still exist, or any damage is evident
(such as wrinkles or tears - holes), the mem-
brane should be replaced. Make sure that the
O-Ring is properly seated in the membrane
cap.