Operational Guide
27
Oxygen is consumed during the measurement. For accurate DO measurements,
water movement of 0.3 m/s is suggested. This is to ensure that the oxygen-
depleted membrane surface is constantly measuring a representative sample.
The use of a magnetic stirrer is recommended. The probe has a built-in
temperature sensor. Make sure it is also in sample. The measured temperature
is indicated on the second LCD line as shown on page 24. Allow the probe to
reach thermal equilibrium before taking any measurement. This can take several
minutes. The greater the diff erence between the temperature at which the
probe was stored and the temperature of the sample, the longer the time will
be.
If the DO temperature exceeds the limits of the
probe, the message “PROBE OUT OF SPEC” will scroll
on the third LCD line and LCD will display dashes. If
the temperature exceeds the probe specifi cation
50 ºC, then “50 ºC” will blink on the display. If interval
logging, the message “OUT OF SPEC.” will alternate
with the Log specifi c messages in both of these cases.
The Log fi le will indicate “ºC!” next to the data. In the
case the temperature sensor is damaged, “BROKEN
TEMPERATURE SENSOR” will be displayed and the
temperature will display “----” along with the unit
tag blinking on the second LCD line. The Log fi le will
indicate “ºC!!” next to the data.
Dissolved
Oxygen
Measurements
Summary of Contents for edge DO
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