Sample requirements, Measurement – Hach-Lange PHC705 User Manual
Page 5
6. Push Read. Wait
until the reading
stabilizes.
7. Do steps 4–6
again to collect the
minimum number of
calibration points
specified in the
calibration options.
8. Push Done to view
the calibration
summary.
Note: The display will
not show "Done" until
the minimum number
of calibration points is
collected.
9. Push Store to
accept the calibration
and go back to the
measurement mode.
Sample requirements
N O T I C E
Some probes are not compatible with specific sample types. Probe damage can occur.
•
Samples must be aqueous. The probe can also make measurements in partially
aqueous or some water-miscible solvents. Read the results with caution because the
full pH scale changes when the solvent system changes.
•
Probes with a Red-Rod reference system are compatible with solutions that contain
silver complexing or binding agents (e.g., TRIS, proteins and sulfides), as they have
an encapsulated reference system.
•
Proteins can collect on the sensing element. Make sure that the probe stays clean
when these types of samples are measured.
•
Do not use the probe in solutions that are out of the temperature range of the probe.
Refer to
•
For low ionic strength (LIS) or high purity samples, use an LIS chamber or a flow cell
to prevent sample contamination.
Measurement
Before measurement:
The probe must have the correct service-life time stamp. Set the date and the time in the meter before the probe is attached.
If the complete traceability is necessary, enter a sample ID and an operator ID before the measurement. Refer to the HQd
meter manual for more information.
A regular calibration is necessary for the best measurement accuracy (refer to
on page 3).
Prepare the probe for use (refer to
Measurement notes:
•
Data is automatically stored in the data log when Press to Read or Interval is
selected in the Measurement Mode. When Continuous is selected, data is only
stored when Store is pushed.
•
Air bubbles under the sensor tip can cause a slow response or an error in the
measurement. If there are bubbles under the sensor tip, carefully shake the probe to
remove the bubbles.
•
For the best stabilization time, condition the probe for several minutes in the sample
or in a solution comparable to the sample in terms of pH and ionic strength before the
initial sample measurement.
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