ATI
Q45D Portable Dissolved Oxygen
Part 4
– Sensor Assembly
Figure 6 - Submersible Sensing Module Assy
Follow the procedure below to prepare the D.O. sensor module for operation:
1. Unscrew the electrolyte chamber from the assembled sensor and also remove the
vent screw from the side of the sensor body.
2. Remove the front nut from the bottom of the chamber and discard the protective
membrane. O-rings are contained in grooves on both the bottom and top of the
chamber. Be sure that these o-rings remain in place.
3. From the package of membranes (either 2-mil or 5 mil) supplied with the sensor,
place a new membrane into the front nut, holding the membrane by its edge to avoid
fingerprint oil from contaminating the membrane.
The membrane is clear and is
separated from other membranes by a light blue paper spacer.
4. Screw the front nut on to the chamber until you feel the o-ring compress. Hand tight
compression is all that is needed. Do not use tools to tighten. The membrane should
be flat across the bottom of the chamber without wrinkles.
5. Fill the chamber with electrolyte until the level reaches the bottom of the internal
threads.
6. Slowly screw the chamber onto the sensor body. A small amount of electrolyte will
run out of the hole from which the vent screw was removed. Place a paper towel
around the sensor to absorb the electrolyte overflow. The electrolyte is harmless and
will not irritate skin. Tighten the chamber until the o-ring at the top of the chamber is
compressed. Once again, do not use tools to tighten.
7. Shake excess electrolyte from the vent hole on the side of the sensor and replace the
vent screw.
