Calibration Set-Up; Requirements; Procedure; Probe Maintenance - VWR DO210 Manuel D'exploitation

If 'Each' is selected, the Up and Down arrow keys will allow you to scroll through the saved
data records. Press
shift up to keep the records in sequential order. For example, if record 3 is deleted, record 4 will
become record 3 and record 5 will become record 4. Press Mode twice to return to the
measurement mode.

CALIBRATION SET-UP

Requirements

1. The approximate true barometric pressure (in millibars [mBar]) at the time of calibration.
2. The approximate salinity of the water to be analyzed. Fresh water has an approximate
salinity of zero. Seawater has an approximate salinity of 35 parts per thousand (ppt).
3. For highest accuracy, complete all calibrations at a temperature as close as possible to the
sample temperature.

Procedure

1. Place 5-6 drops of clean water (tap, distilled, or deionized) into the sponge inside the
calibration bottle. Turn the bottle over and allow any excess water to drain out of the bottle.
The wet sponge creates a 100% water-saturated air environment for the probe, which is
ideal for calibration, transport, and storage of the DO probe. For calibration, the probe
remains in a water-saturated air and is not submersed.
2. Slide the probe into the calibration bottle. Be sure the membrane does not touch the
sponge.
3. Turn on the unit by pressing
temperature readings to stabilize.
4. Press CAL.
5. The LCD prompts for the local pressure in mBar. Use the ∆ and ∇ keys to increase or
decrease the pressure value respectively. See the section titled 'Conversions' to convert
barometric pressure units to mBars.
6. When the proper pressure displays, press
right of the display. Once the value in the main display stabilizes, press
the salinity compensation procedure.
7. The display prompts for the approximate salinity of the water to be analyzed. Use the ∆ and
∇ keys to increase or decrease the salinity compensation value to the value of your sample
(between 0 to 40 parts per thousand [ppt]). When the correct salinity displays, press
8. The unit holds calibration even if it is powered off. However, it is recommended to check
calibration with each use and recalibrate as necessary to prevent drift. Dissolved oxygen
readings are only as good as the calibration.

PROBE MAINTENANCE

To clean the probe, use the sandpaper disks in the VWR membrane kit (part number 664-0005).
In addition to the sandpaper, you may try a chemical cleaning. To clean the electrodes
chemically, perform an ammonium hydroxide soak.
1. Remove membrane cap and rinse the probe with clean water (tap, distilled, or deionized).
2. Turn unit off, or disconnect probe.
3. Obtain either:
• 14 % lab strength ammonium hydroxide and soak for 2-3 minutes
• 3% household cleaning strength ammonia and soak overnight (8-12 hours)

to delete the selected record. All records after the deleted record will
. Wait 10 to 15 minutes for the dissolved oxygen and
once to view the calibration value in the lower
4
again to move to
.