What solutions should I use for storage?

Selecting the appropriate storage solution for your pH electrode will protect your electrode from irreversible damage and keep your readings accurate. I learned this at the expense of a brand-new pH electrode, which was ruined in my lab by distilled water. Proper storage solutions will maintain ionic balance and hydration that are critical to the functioning of your electrode.

Always use the manufacturer-recommended concentrations. Most electrodes need 3M-4M potassium chloride solution. I verify the concentrations every month using a conductivity meter. Using too low or too high a concentration will cause an electrolyte imbalance, which causes reference electrode failure and measurement drift.

Storage containers are as important as the solutions that you use. Use sealed, opaque containers that prevent evaporation and exposure to light. I replace storage caps quarterly to ensure containment is acceptable. Never use containers made of metal because they will leach ions into your solution and contaminate it.

Following storage, I verify the electrodes' operational effectiveness in a saline solution. If the bulbs are glossy, this is a sign of adequate hydration. A cloudy appearance on the bulbs indicates dehydration damage. I log the bulbs' weekly inspection notes in our maintenance log and describe their appearance in the bulbs.

Solution replacement follows strict schedules. Change storage solutions monthly regardless of appearance. Contaminants accumulate invisibly. I mark calendars for solution replacement to avoid memory lapses that have previously damaged equipment.

Travel storage needs special attention. Use leak-proof containers with absorbent material. I secure electrodes vertically during transport. Field technicians receive spill kits to prevent solution loss during mobile operations.

Read the full article: pH Meter Calibration: Step-by-Step Guide