Dissolved Oxygen (DO) Measurements
Measurement Preparation
Before taking measurements, perform the calibration described above if necessary. In addition,
perform the % SALT and ALTITUDE compensation adjustments as described below:
% SALT Compensation
Slide the O
2
/DO switch to the DO position. If the measured liquid is pure water or is known
not
to have a salt content, set the % Salt factor to 0%.
1.
2.
3.
Press the % Salt key. The display will indicate
0%
on the middle portion of the LCD
display and
S
on the bottom portion of the LCD.
Pressing the Factor Adj. key once will add 1% to the salt factor.
Press the Factor Adj. key until the correct factor is displayed.
4. Press the % Salt key to store the factor.
NOTE: 1% = 10 ppt (parts per thousand)
ALTITUDE Compensation
The meter has a default calibration for sea level operation (0 meters). Any significant
deviation from sea level requires a compensation adjustment. Perform the following steps to
do so:
1.
2.
3.
Press the ALTITUDE key and the display will indicate a “0” in the middle of the LCD
and an “H” on the lower portion of the LCD.
Press the Factor Adj. key once to add 100 meters, twice to add 200 meters, and so on.
Maximum compensation is 3900 meters.
Once the desired compensation is displayed, press the ALTITUDE key again to store
the value.
Taking Measurements
1.
2.
3.
Immerse the probe in the solution under test. For best automatic temperature
compensation, immerse the probe to a depth of at least 4" (10 cm).
Wait until the display stabilizes.
The velocity of the liquid coming into contact with the probe must be at least 0.6 to 1
ft/min (0.2 to 0.3 m/s). If the solution is standing, stir the solution with the probe or use
an agitator.
Rinse the probe with clean water after each use.
4.
Oxygen in Air (O2) Measureme
nts
Follow the same steps above for DO measurements except for the variations described below:
1. Slide the O
2
/DO switch to the O
2
position.
2. The display will indicate the oxygen air value in %.
Temperature Measurements
The lower display will indicate the temperature of the measured solution. Press the C/ F key to
change the temperature units.
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o
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407510
V7.0 10/06
EXTECH [ EXTECH INSTRUMENTS CORPORATION. ]
