PASCO PS-2108 Dissolved Oxygen Sensor - Manual (Page 10)

PASPort Dissolved Oxygen Sensor Model No. PS-2108
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General Sampling Procedure
1. Immerse the Dissolved Oxygen probe into the test solution until the silver temperature
compensation band is submerged.
2. Click the Start button on the DataStudio tool bar or select Monitor Data from the
Experiment menu.
3. Gently, swirl the probe for a minute or two until the dissolved oxygen readings stabilize
around a value. As an alternative, use a magnetic stirrer to slowly stir the test solution (do
not stir fast enough to entrain air bubbles or form a large vortex.
Measurements in a Controlled Laboratory Setting
In a laboratory setting, you can make long-term measurements of dissolved oxygen levels by
gently and continuously stirring the solution with a magnetic stir plate and stir bar. Minimize
the surface area of the atmosphere/liquid interface to retard gas exchange with the
atmosphere. A vessel such as an Erlenmeyer flask or a large test tube works well.
Note: DO NOT USE MINERAL OIL, as it is difficult to clean from the membrane.
Using the Dissolved Oxygen Sensor with other PASCO Sensors:
Some PASCO sensors, including the Dissolved Oxygen Sensor, emit electrical signals into
the test solution and may interfere with other sensors taking simultaneous measurements. If
you want to take simultaneous measurements with the Dissolved Oxygen Sensor and another
PASCO sensor (such as the Conductivity Sensor or pH Sensor), conduct controlled
experiments and ensure that no intra-sensor interference occurs under your experimental
conditions.