16
MW180 pH / mV / EC / TDS / NaCl / Temperature Bench Meter
Storage
To minimize clogging and ensure quick response time, the glass bulb and the junction
should be kept hydrated.
Add a few drops of
MA9015
Storage solution to the protective cap. Replace the storage
cap when the probe is not in use.
Note:
Never store the probe in distilled or deionized water.
Regular Maintenance
y
Inspect the probe. If cracked, replace the probe.
y
Inspect the cable. Cable and insulation must be intact.
y
Connectors should be clean and dry.
y
Rinse off salt deposits with water.
y
Follow storage recommendations.
For refillable electrodes:
y
Refill the electrode with fresh electrolyte solution (see the electrode’s specifications
to select the correct refilling solution).
y
Keep the electrode upright for 1 hour.
y
Follow the storage procedure above.
If electrodes are not maintained correctly both accuracy and precision are affected. This
can be observed as a steady decrease in the slope of the electrode.
The slope (%) indicates the sensitivity of the glass membrane, the offset value (mV)
indicates the age of electrode and provides an estimation when the probe needs to be
changed. The slope percentage is referenced to the ideal slope value at 25 °C.
Milwaukee Instruments recommends that the offset does not exceed ±30 mV and that the
slope percentage is between 85-105%.
When the slope value drops below 50 mV per decade (85% slope efficiency) or the offset
at the zero point exceeds ± 30 mV, reconditioning may improve performance, but a
change of electrode may be necessary to ensure accurate pH measurements.
Electrode Status
MW180
displays electrode status after calibration. See probe icon on the LCD screen.
The assessment remains active for 12 hours and is based on the electrode offset and
slope during calibration.
