Hanna Instruments HI 9829 - Manual (Page 81)

81
APPENDIX A - PROBE MAINTENANCE
The HI 7698292 probe maintenance kit includes HI 7042S (electrolyte solu-
tion for D.O. sensor), spare membranes with o-rings for D.O. sensor, a small
brush for cleaning EC , o-rings for sensor connectors and a syringe with grease
to lubricate these o-rings.
General Maintenance
• Inspect all sensor connectors for corrosion and replace sensors if necessary.
• Inspect sensor o-rings for nicks or other damage and replace sensor if neces-
sary. Lubricate only with grease from kit.
Use only the supplied grease as some lubricants can cause the
o-rings to expand or affect the turbidity calibration standards.
• After prolonged storage or cleaning, calibration of the sensors is required.
• After use rinse the probe with tap water and dry it. The pH electrode bulb must
be kept moist. Dry the D.O., EC and EC/Turbidity sensors. Dry ISE sensors and
return to their storage caps if they will not be used for a period of time.
• Check GLP data under “Status” to ensure the sensor is still functioning
properly.
pH and pH/ORP Sensor Maintenance
• Remove the sensor protective cap. Do not be alarmed if any salt deposits are
present. This is normal with pH/ORP electrodes and they will disappear when
rinsed with water.
• •• •• Shake down the sensor as you would do with a clinical thermometer to eliminate
any air bubbles inside the glass bulb.
• •• •• If the bulb and/or junction are dry, soak the electrode in HI 70300 storage
solution for at least one hour.
• •• •• To ensure a quick response time, the glass bulb and the junction should be kept
moist and not allowed to dry. Store the sensor with a few drops of HI 70300
storage solution or pH 4.01 buffer in the protective cap. Tap water may also be used
for a very short period (few days).
Never use distilled or deionized water to store pH sensors
• •• •• Inspect the sensor for scratches or cracks. If any are present, replace the sensor.
• Cleaning procedure: clean the sensor frequently by soaking it for 1 minute in
HI 70670
or HI 70671 cleaning solution. After cleaning soak the sensor in
HI 70300
storage solution before taking measurements.