Don’t touch the electrodes of your conductivity probe. They are coated in platinum black, which can only be loosely attached to the underlying platinum. For more detail, the platinum electrodes are electroplated in a particular kind of platinum coating which gives it more surface area. Since it is platinum, things don’t attach to it very well. The coating can very easily be rubbed off and it cannot be reapplied. The probe will still work, but less effectively.
To clean it, soak it in a mild acid like vinegar. Vinegar is particularly effective at removing solidified salts. If simple vinegar doesn’t work, try using hot vinegar. It won’t smell very nice, but it is a small price to pay. Use progressively stronger acids and agitate the probe to remove more difficult fouling agents.
The probe is made of glass and can break in lots of sharp pieces which you won’t be able to find very easily. The electrode-end is particularly easy to break.
Store it in the included plastic end-cap. It can be stored dry or soaked in a solution. If it is stored dry, it is a good idea to make sure it is cleaned with distilled water to prevent surface deposits that might be difficult to remove later.
pH probes must be kept in a solution. If it dries, it might not be able to be rehydrated. There is a liquid junction in the probe which must be able to make contact with the solution to be measured.
The small glass bulb at the end is extremely delicate and also doesn’t like being dry.
If the pH probe isn’t be used, store it in storage solution; there are countless places to buy it online. In a pinch, use pH 4 buffer solution that is saturated with salt.
Use a mild acid to remove surface deposits from the probe. The body is plastic, so don’t use a strong acid that might eat away the plastic.
Like the conductivity probe, the glass bulb at the end is easy to break.