In-Situ TROLL 9500 Operators Manual - Manual (Page 89)

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TROLL 9500 Operator’s Manual 0095110 rev. 007 01/09
SECTION 13: DISSOLVED OXYGEN—POLAROGRAPHIC
Preparation for 100% D.O. Calibration in Water
The bubbler cal kit for the Polarographic D.O. sensor comes with
(1) Battery-powered air pump and 2 alkaline D-cells, (2) Bubbler
cup with aquarium stone, tubing, check valve and pinch valve, (3)
Grey PVC adapter to support the TROLL 9500 in the top of the
bubbler cup.
1. Install the batteries in the portable air pump as shown in the
diagram on the inside of the lid.
2. Fill the bubbler container almost to the top with clean water. The
optimum amount depends on the volume of the sensors installed
in the MP TROLL 9500.
TIP: Tap water is fine, unless it is high in salinity. It is easier
to achieve 100% oxygen saturation in low-salinity water.
Distilled water is readily available and works well.
3. About 10 minutes before calibration, turn on the bubbler. Regu-
late bubbling with the pinch valve. For best results, run at the full
mOW
4. Before beginning the calibration procedure, note the membrane
thickness stamped on the membrane module.
5. With the D.O. sensor installed and plugs or sensors in the
other sensor ports, rinse the front end of the MP TROLL 9500
thoroughly in clean water to remove contaminants and traces of
mUIDS
6. When ready to calibrate, place the adapter
securely in the top of the bubbler housing
and insert the front (sensor) end of the MP
TROLL 9500 into the adapter.
s
aeration path. Rotate as necessary to
prevent air bubbles from collecting on
the membrane surface.
s
mm) in the aerated water.
Allow a few minutes for the temperature to stabilize,
especially if you plan to enter a temperature dependent
value from a look-up table.
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Preparation for 100% D.O. Calibration in Air
TIP: Before beginning the calibration procedure, check
the side of the membrane module for the membrane
thickness.
1. With the D.O. sensor installed and plugs or sensors in the
other sensor ports, rinse the front end of the MP TROLL 9500
thoroughly in clean water to remove contaminants and traces of
mUIDS
2. Dry the D.O. sensor membrane by shaking the probe and/or
gently wiping with a soft swab or the corner of a tissue.
3. Rinse the empty Cal Cup and attach it to the MP TROLL 9500.
Thread the Cal Cup onto the body until it is seated against the
o-ring, then back off slightly to avoid overtightening.
4. Invert the TROLL with Cal Cup attached and remove the black
end cap from the Cal Cup.
5. Gently fill the Cal Cup with clean water until the temperature
sensor is completely covered and the membrane at the tip of the
D.O. sensor is in air. If any water splashes onto the membrane,
gently blot the center of the membrane
with a clean cotton swab or the corner of
a soft lint-free tissue.
6. Loosely attach the end cap to the Cal
Cup. For proper venting, a small hole in
the threads of the cap should be at least
partly visible to achieve ambient pressure
conditions.
You may wish to use a clamp or other
support to maintain the TROLL 9500 in
this inverted position.
Allow a few minutes for the temperature to stabilize,
especially if you plan to enter a temperature dependent
value from a look-up table.
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