Hach-Lange PHC725 - Manual (Page 7)

6. Push Read. The display shows "Stabilizing" and a progress bar as the reading
stabilizes. The display shows the value of the check standard and Check Standard
Passed or Check Standard Failed.
7. If the display shows Check Standard Passed, the check standard measurement is in
the accepted limits. Select Done to continue the sample measurement.
8. If the display shows Check Standard Failed, the measurement is out of the accepted
limits. A calibration is recommended. Make sure that the limits are set correctly at the
PHC725 Settings menu. If the acceptance criteria is set to "Cal Expires on Failure:
Yes", the display shows the calibration icon and a question mark until the probe is
calibrated again. To correct the probe calibration and status indicator, calibrate the
probe (refer to
Calibration on page 3).
Advanced operation
This section gives instructions about menu navigation and available options. Change
parameter-specific settings through the Full Access Options menu.
The settings that can be changed are shown in
Table 2 .
Table 2 Parameter-specific settings
Setting Options
Measurement Options
• Resolution
• Upper and lower range limits
Calibration Options
• Buffer set
• Buffer set values (if Custom Buffer Set selected)
• Reminder
• Minimum Cal points
• Slope limit
Check Standard Options
• Standard (temperature compensated buffer or custom at 25 °C (77 °F))
• Reminder
• Acceptance criteria
• Standard value at 25 °C (77 °F) (if custom standard selected)
Units
• pH
• mV
Change measurement options
Methods are groups of default or user-defined settings related to specific applications. If
the meter is set to the default method, a prompt for a new name method shows. The
settings are saved with this name to identify them from the default method settings, which
cannot be changed. Use a saved method as an alternative of many adjustments to the
individual settings. Changes made to a user-defined method are automatically saved with
the existing name. Save different methods for the same probe on each meter.
1. Make sure that a probe is connected to the meter.
2. Push and select PHC725 Settings.
3. Select Modify Current Settings.
4. Select Units. Select pH (default) or mV.
Note: Use the mV option to find the probe offset in a pH 7 buffer or to measure the slope. Both
units show when the Detail Display mode is selected.
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