YSI DO200 - Manual (Page 6)

THE LCD DISPLAY A
BA
T SAL ppt mBar
% ppm
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2
3
4
5
7
C
CAL
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Figure2. LCD Display
1. BAT: Low battery indicator.
2. CAL: Calibration mode indicator.
3. SAL ppt: Displays during calibration
when user is prompted for the
approximate salinity of the sample in
parts per thousand (ppt).
4. mBar: Displays during calibration to
prompt user for barometric pressure.
5. Main display for dissolved oxygen
values.
6. %/ppm: Unit indicators.
7. ºC: Temperature display.
OPERATIONAL PROCEDURES
Press to turn the unit on or off. The instrument will perform a self-diagnostic test, during which
an “ovEr” message may appear on the display. This is normal. After the warm up is complete
the message will disappear. After the self-diagnostic test completes, the temperature displays in
the lower right of the display, and the unit is ready for operation. Immerse the probe halfway into
the sample solution. If possible, do not allow probe to touch any solid object in the solution.
Allow no air bubbles around the probe. When the unit is not in use, turn it off to save battery life.
NOTE: During an oxygen measurement, the probe must be moved approximately 1/2 ft per
second to overcome the inherent consumption of oxygen by the sensor. When using the 200-
BOD lab probe, however, simply use the probes self-stirring feature.
MEASUREMENT MODES
This unit provides three distinct measurements:
1. Temperature - Current solution temperature continually displays.
2. Dissolved Oxygen % - Measurement of oxygen in percent saturation.
3. Dissolved Oxygen ppm - Measurement of oxygen in ppm (mg/L).
Carefully observe the units displayed at the far side of the LCD to determine the desired mode.
CALIBRATION SET-UP
Requirements
1. The approximate pressure (in millibars [mBar]) of the region to be measured for dissolved
oxygen.
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.
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