18
4.2 Taking Measurements
Follow these general rules when taking measurements: keep the
membrane free from contact with solid objects, provide stirring of the
solution—this helps to overcome the oxygen consumption of the probe
and prevents air bubble entrapment, do not strike the probe against hard
surfaces, and do not submerge the cable for extended periods.
1. Rinse the probe thoroughly with DI
water or rinse solution.
2. Select the appropriate measurement
mode. Press
MODE
to toggle between
modes:
a. Percentage Saturation (%)
b. Concentration (mg/L) or
(ppm)
c. Temperature (T)
3. Dip the probe into the sample. Stir the
solution gently with the probe.
4. Allow the reading to stabilize and
observe the reading.
To change the concentration units see Section
5.3—
Selection of mg/L or ppm
.
4.3 Pressure & Salinity Compensated Measurements
During measurement the dissolved oxygen reading is automatically
compensated for salinity and pressure based on values entered in the
setup menu. For the most accurate DO readings, ensure that pressure
and salinity are adjusted accordingly from the setup menu. The factory
default values are 760 mm Hg (101.3 kPa) barometric pressure (sea
level) and 0.0 ppt salinity (no salinity). See Section 5.9 —
Pressure &
Salinity Adjustment
.
%
A
mg/l
A
MODE
MODE
TA
