YSI DO200 - Manual (Page 5)

4. Keep the probe’s gold cathode clean and textured (when properly maintained it has a matte
finish). If it is tarnished (from contact with certain gases), or plated with silver (from
extended use with a loose or wrinkled membrane), then clean it, following the instructions in
“Probe Maintenance”.
5. To prevent the membrane and electrolyte from drying out, store the field probe in the
calibration bottle with the moistened sponge and the lab probe in a BOD bottle with 1 inch of
water to keep them in a saturated air environment.
PROBE PREPARATION
The DO200 probe ships with a dry, protective membrane. To install a new membrane cap on the
probe:
1. Unscrew probe membrane cap and discard.
2. Fill a new cap with Oxygen Probe Solution. Prepare according to directions on the solution
bottle.
3. Thread filled membrane cap onto sensor.
4. Allow sufficient warm-up time for initial use (10-15 min). During this time an “ovEr” message
may appear on the display. This is normal. After the warm up is complete the message will
disappear.
BATTERY INSTALLATION
An initial display of “LOW BAT” on the LCD indicates approximately
one hour of battery life for unit operation within specifications. Replace
battery when “LOW BAT” appears on the LCD.
To replace battery, remove the two battery cover screws and the
battery cover and o-ring. Replace the 9V battery. Replace the battery
cover and o-ring (be sure to align the o-ring correctly to prevent a bad
seal) and fasten the two battery cover screws for the splash-
resistant feature.
Figure 1.
Battery Installation
THE KEYPAD
1. : Turns the unit on or off.
2. MODE: In normal operation, toggles display between Dissolved Oxygen in % air saturation
and Dissolved Oxygen in ppm (mg/L). In Calibration mode, exits current calibration and
displays the next calibration parameter.
3. CAL: In normal operation, changes the mode from Normal to Calibration. See Calibration
Set-up.
4. : In Calibration Set-up, press this key to save the current parameter to memory.
5.
Δ and ∇ Keys: Increases or decreases the display value as desired.
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