LaMotte 1761 Manual - page 12
12
DISSOLVED OXYGEN MEASUREMENT
(Be sure the electrode is f lled and fully polarized. Calibrate daily.)
1. Cover the electrode with the electrode cap. The sponge in the electrode
cap should be moistened (not soaked) with distilled water or tap water.
2. Press ON/OFF to turn the meter ON. The meter will self calibrate.
3. Press and hold MODE to select the desired unit of measure.
4. Remove the electrode cap.
5. Place the electrode in the sample to be measured. Stir the sample with
the electrode.
6. Wait for the reading to stabilize.
7. Press ON/OFF to turn the meter OFF. Rinse the electrode with distilled
water or tap water. Replace the electrode cap.
NOTE:
- The unit of measure selected when the meter was last turned OFF
will be retained.
- Stir the sample with the electrode to remove any air bubbles that may
be trapped on the membrane surface and to obtain accurate results.
- Do not submerse the electrode above the bottom edge of the electrode
collar.
- For maximum accuracy, allow suff cient time for the temperature of
the probe to reach the temperature of the sample before taking a reading.
The larger the difference in temperature between the electrode and the
sample the longer it will take for the reading to stabilize. Stabilization
will be indicated by a stable temperature reading on the display.
Stabilization time can vary from ten (10) seconds to f ve (5) minutes.
-The DO Tracer uses a polarographic sensor, which consumes oxygen
at the sensing surface. This requires a constant movement of the sample
across the membrane to maintain a constant dissolved oxygen level. It
is recommended that the sample be stirred gently with the electrode as
the measurement is made, or if in a laboratory environment, the sample
should be stirred using a stir plate.
MEASURE