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DO MEASUREMENT
14. DO MEASUREMENT
1. Select measurement units of convenience. Press
SETUP
to change temperature or pressure
measurement units.
2. Press
RANGE
to access the preferred measurement units; mg/L or % saturation.
3. Routinely Inspect probe for biofouling. Routinely clean off the probe with clean water (between
measurements). Biologically active waters may require more frequent cleanings. Ensure weeds,
debris, or other materials are not coating the protective guard as this will block sample circulation
preventing sample from reaching the active measurement surface.
4. Verify pressure and temperature measurements are reading correctly and that the probe has
been calibrated in accordance with sampling protocols.
5. When measuring across a temperature gradient, (i.e. the car is hot and the waters cool), allow
the probe to come thermal equilibrium with the water being sampled.
6. The
HI98198
with
HI764113
have been designed for dissolved oxygen water quality
measurements in urban and natural waters. It may be used for discrete spot sampling using the
meters Log on Demand function. The maximum depth rating for the probe is 20 m and should
be adhered to.
7. Select a water sampling site that will have a representative sampling. Position the probe if
possible, facing flow to minimize bubble collection or fluid cavitation. The probe should be
measuring the partial pressure of the dissolved oxygen in water. Gas bubbles have a greater
partial pressure due to the surface tension of the bubble. Noisy or erratic measurement or higher
measurements are possible.