2. pH CALIBRATION, CARE & MAINTENANCE
A. pH Information & Maintenance
[The pH electrode included with the HydroMaster (HM-500) has been carefully
handcrafted. For optimal performance and probe longevity, carefully follow the
instructions below.]
• The life of a pH electrode will depend on how it is used and maintained.
(It is backed by a 6 month factory warranty)
• Inside the glass bulb of the pH sensor is a Potassium Chloride (KCl) solution.
It is also in the cap of the pH sensor.
After usage, always store the probe in the sensor cap. For long-term use,
purchase a KCl solution and use it for storage.
• Always keep the electrode wet. If the electrode dries it may shorten its life
and the pH reading may not be as accurate. If this is the case, immerse the
electrode in KCl storing solution for a minimum of 2 hours to re-saturate.
• Rinse the electrode with clean water or distilled water (if available) between
or after measurements to eliminate cross contamination of solutions.
[Warning]
• Avoid direct sunlight or heat.
• Do not touch the glass part of the electrode with your hands or hard
materials.
• Exposure to highly basic or acidic solutions, extremely high and/or low
temp water may cause damage to the electrode, thereby shorten its life.
• If the measuring time of the pH meter slows down or if the pH reading is
unstable, it’s most likely time to change the electrode.
• When wiping the electrode with a dry cloth, be careful of static electricity,
as it may delay pH readings.
B. pH Operation
1. The HM-500 is factory calibrated. However, we recommend initially
re-caibrating the instrument before 1st usage and then once a month
thereafter.
2. Remove the sensor cap. Be careful not to spill KCl storage solution from
the cap.
3. Immerse the electrode in the solution you would like to measure and stir
gently to remove air bubbles surrounding electrode. (Air bubbles can
affect accuracy of pH readings).
4. Measurements take between 10-60 seconds to stabilize.
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