Hach-Lange LDO10130 - Manual (Page 7)

• Default
1. Make sure a probe is connected to the meter.
2. Push and select LDO101 Settings.
3. Select Modify Current Settings.
4. Select Units. Select mg/L (default) or %.
5. Select Measurement Options and update the settings:
Option Description
Resolution Sets the resolution:
• 0.1—Fast (0.35 mg/L)/min
• 0.01—Fast (0.35 mg/L)/min
• 0.01—Medium (0.15 mg/L)/min (default), or
• 0.01—Slow (0.05 mg/L)/min
The resolution affects the number of decimal places and the stabilization
time. Higher resolution measurements take more time to stabilize.
Measurement
Limits Set the measurement limits—Lower limit (default: 0.0 mg/L; 0%) or Upper
limit (default: 20.0 mg/L; 200%).
The measurement limits can be set to match the acceptable values for the
sample. When the measurement is above the upper limit setting or below
the lower limit setting, the meter shows an "Out of limits" message. This
message is an alert to a potential problem with the process conditions.
Salinity
Correction Sets the salinity correction—Off (default), Manual or Auto (connect
conductivity probe).
Salinity lowers the solubility of dissolved oxygen in water. To correct for
salinity in the sample, set salinity correction to manual and then enter the
salinity value.
Note: When the HQ40d meter is used, a conductivity probe can also be
connected for automatic salinity measurement and correction. The
parameter setting for the conductivity probe must show salinity.
Salinity Value Sets the salinity value—‰ (default: 35.0 ‰).
When salinity correction is set to manual, sets the salinity value of the
sample. Salinity can be measured with a conductivity probe.
Pressure Units Sets the pressure units—hPa, mBar, inHg or mmHg.
The meter shows the atmospheric pressure at the current elevation, which
is necessary for accurate measurements.
Note: This pressure reading will not agree with readings from sources
such as weather stations, which report atmospheric pressure at sea level.
Averaging
Interval Sets the averaging interval—Off, 30, 60, 90 seconds, 3, 5 minutes.
The averaging interval is useful for samples that contain a lot of air
bubbles, for example in an aeration basin. The air bubbles cause the
dissolved oxygen readings to vary greatly from one reading to the next. To
make the readings more consistent, increase the averaging interval. The
meter will take measurements at the same frequency but show only the
average over a longer interval.
Note: Labels and options may vary depending on the units selected.
6. If prompted, enter a name for the new method settings. Additional changes made to
the settings of an existing method are automatically saved with the same method
name.
7. Push EXIT until the meter returns to the measurement mode.
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